Before I answer you
Before I answer your question, please read this advise as I did cycle through Patagonia and I can tell you this:
- The roads are not that easy, sometimes given the roads surface it was challenging doing 50 km in a day;
- When the roads were alright, then the weather was very very difficult. The wind blows strongly in the Argentinian side and the Southern you get the stronger those winds get. It can be even challenging to walk (check pictures from the South Patagonia, trees are growing horizontally). So you can have the sunny but windy Argentinian side, or the rainy (heavy sometimes!!) Chilean one. Sometimes the weather was so bad, that we had to take a rest day;
- Argentinian and Chilean sucks at mapping or road signs (at least in 2008). Both do not match in terms of how far is the next town, and sometimes even both are incorrect compared to what we measured! Locals only know distances in "hours by car", not very helpful (at least it seems that there are finally now Google Maps of Chile and Argentina, that did not exists before, so I do not know how good they are);
- Finally, the important question when you do Patagonia by bicycle (or any other means) is not where is the next accomodation, not at all. It is where can I "refuel" next? For a car or motor bike, it is the tank station. For a cyclist, it is food and more importantly water! You will need water for cooking, for drinking, and sometimes other purposes. And water can be scarce on the Argentinian side. So get a water filter, and ask fellow travellers cycling South to North where is the next water refuel point.
However, the effort is well worth what you will experience! It is a beautiful country, extremely beautiful, people are extremely nice and helpful.
And here is the catch: if you plan on doing 100km/day, then either you are superman (and there are a few, but I'm not!) or you'll get disillusioned! But even if you're superman (who knows), what a pity to manage to fight so hard against bad road, bad weather, broken bike parts, a combination of all those, etc. and not having the time to enjoy the landscape because you need to rush on and continue!
One last piece of advice (if again you're not superman), take a rest day from time to time (e.g. once a week) you will need it for various reasons:
- Your body can't follow your mind and you're completely tired and used;
- You will need to wash your clothes or repair your broken spikes or other bikes parts you did not think of, it can take a big part of a day;
- It is nice to enjoy every 1000km a nice restaurant;
- when do you plan on taking on the views? Most of the time, the best views are not from the most direct North-to-South route, but one on the side tracks.
When I left for Patagonia, I took a guide book with me (e.g. Lonelyplanet, Footprint, etc.) in case I need to find accommodation. But you don't need to really.
First of all and most of the time you will be camping among sheep or lamas. And second and last of all, when you get to a "city" it is small enough to get through most camping/guest houses/hotels in a short time to find where you want to sleep. There aren't that much choices and usually they are well indicated/signed.
And when all of the above does not work, open the guide book and you will find an answer. It does not require battery nor to have a network reachable :-)
But as I said before, accommodation should not be a question, you should worry about. More importantly is: take great care of your bike, and of the replacement parts you're going to take with you, of the tooling to maintain and repair your bike, on good clothes and camping gears, be ready to carry food for 7 days and water for 2-3 days (worse cases). Be ready to do wild camping for 7 days in a row.
Do it! Cycling Patagonia is extremely rewarding!
But don't take it light! Accommodation is a no problem, having a shower neither. Getting food and water is, you need to plan each time you have an opportunity to refuel.
Superman can probably cycle from Bariloche to Ushuaia in 3 weeks and will be able to enjoy, visit, take on the views. We mere mortals could potentially do it also in 3 weeks, but then what for? Do a shorter trip, or take longer vacation. If you are a good sport person, then you will probably be able to easily do 60-70km/day in Patagonia, but even if you are that sportive, take a rest day every 7 days (or less). Your body will thank you for it.