What is the best way to get temporary smartphone data service across multiple countries?

Question

My specific question is about Europe: I'm going to be going through Germany, Czech Republic, Austria, Slovenia, Croatia, and possibly Bosnia/Herzegovina and/or Montenegro. (I live in the USA.) However, I'm interested in the overall question for travel in general as well. Basically what I want to know is what is the overall least painful way to get access to a mobile data network while travelling among several countries.

I have seen previous questions here, here and here. The main three options described there are:

1. Use an international roaming option from your own home-country cell company.
2. Use an international SIM card such as keepgo or the like.
3. Buy a local SIM card in every individual country you travel to.

Option #1 is not available for me as I use TMobile prepaid which doesn't offer international data roaming. Three years ago I went to several countries in western Europe and basically used option 3, but there I was just using voice/text because I didn't have a smartphone at that time. It worked, but it was a bit of a hassle, not least because it was difficult to get clear information about what will happen when you buy a SIM card in one country and use it in another country. For this trip data is more important to me than voice/text (I could probably forgo voice/text entirely), but the multi-country issue is still the big question mark.

What I'm wondering, beyond what is covered in the other questions, is essentially which of solution #2 and #3 is overall more practical. Specifically:

1. Is it always the case that every single national border crossing means you need a new SIM card to avoid impractically high fees? Most of the questions I've seen about this are from before the recent EU regulations on roaming charges. I'm not an expert on those regulations, but from what I can find they seem to have somewhat lessened the pain of multi-country travel. Are there are rules of thumb as far as roaming rates (e.g., if you go from one country to a neighboring country, will the rate increase typically be less than if you go to a more distant country)?
2. At what point does the hassle of buying, installing, and adding money to multiple SIM cards (with the language-barrier problems likely to be present at each step) outweigh the drop in cost? Also, there can be money wastage associated with getting a new card without using everything on the old card. On some of the country-specific provider sites I looked at, it's not clear what will happen if you take one of these prepaid data SIMs outside the country. Will they just not work, or will rates just skyrocket?
3. How does performance compare between the local providers and a package deal like keepgo?

Basically I'm looking for practical guidance on where the happy medium is between keepgo's simple "$8/day 50MB" and the opposite extreme "maybe you can get cheaper rates by buying 5 different SIM cards and loading them with just the right amount of money".

Answer 1

Is it always the case that every single national border crossing means you need a new SIM card to avoid impractically high fees?

Not always, there are some international service providers that charge no roaming fees - in Africa. I'm not aware of any such offers in Europe.

Most of the questions I've seen about this are from before the recent EU regulations on roaming charges. I'm not an expert on those regulations, but from what I can find they seem to have somewhat lessened the pain of multi-country travel.

Wikipedia has the details. In 2013, the limit is €0.45/MB, starting next year it will be €0.20/MB. But note that the regulation is not valid in Bosnia/Herzegovina and Montenegro. Compared to that, keepgo is still a pretty good deal, unless you really only want to check your email (and have a way to ensure that that's all the data traffic yout smartphone does).

Are there are rules of thumb as far as roaming rates (e.g., if you go from one country to a neighboring country, will the rate increase typically be less than if you go to a more distant country)?

No. There may be tariffs where this is the case, but not in general.

At what point does the hassle of buying, installing, and adding money to multiple SIM cards (with the language-barrier problems likely to be present at each step) outweigh the drop in cost?

That depends on the cost (i.e. how much data you're planning to use) and how you value the hassle. Both are going to be pretty high.

On some of the country-specific provider sites I looked at, it's not clear what will happen if you take one of these prepaid data SIMs outside the country. Will they just not work, or will rates just skyrocket?

If they really don't list international roaming charges at all, they will probably stop working. But it's unlikely any provider would forego the chance to collect exorbitant charges.

How does performance compare between the local providers and a package deal like keepgo?

You mean speed and coverage? Keepgo will need to use the network of one of the local providers. It may or may not be the best-performing one.

Basically I'm looking for practical guidance on where the happy medium is between keepgo's simple "$8/day 50MB" and the opposite extreme "maybe you can get cheaper rates by buying 5 different SIM cards and loading them with just the right amount of money".

That depends mainly on how much data you use and how long you'll be staying in each country. Keepgo looks like a great deal if you use 10-50 MB per day and stay less than a week in each country. If you stay longer and/or need more data, the 5 different SIM cards are probably better. If you use very little data, it's probably best to just get one SIM card and live with the roaming charges. In Germany, Aldi Talk has an add-on package that gives you 60 MB total, valid within the EU for 7 days, for 5 EUR.

Answer 2

Since the original question was posed, another possibility has appeared: Google Fi.

One must have a US account and live (mostly) in the US. However, significant overseas use is inexpensive and the service reaches a lot of countries. Android devices work best; iPhones are possible with some features not working quite so well.

EDIT June 8, 2021: several comments report that while one must have a US address to sign up, Google Fi now tolerates use by people who live outside the US.

I use the word "tolerates" deliberately, as Google Fi's current Terms of Service do not permit these uses. Under "Using the Services," this appears:

The Services are offered only to residents of the United States. The Services must be primarily used in the United States (territories not included) and are not intended for extended international use. Further, the Services are designed for use predominantly within our network. If your usage outside our network is excessive, abnormally high, or cause us to incur too much cost, we may, at our option and sole discretion, suspend your Google Fi account, terminate your service, or limit your use of roaming.

(emphasis added)

Thus, use of Google Fi primarily overseas or by a non-resident of the US still violates Google's ToS. I don't dispute that the commentors have had the experiences they report, but prospective users should be aware of the prohibition and keep Caveat Emptor in mind.

Answer 3

Option 3 with the local SIM cards is not that easy anymore. At least in germany the providers are required by law to check your ID. While you can still buy a card at aldi for example, you need to activate it online or offline. Not even sure it works at all without a german passport.

If #1 is not possible, in my opinion #2 is the way to go.