Don't sweat this too much. First of all, we are talking $25-$50 here for the difference between $300,000 and $1,000,000 of coverage.
Second, think about how health-care billing works in the US. Let's say you have some horrible accident and are in the hospital for two weeks. Two months later, the hospital will send a bill for $250,000 to insurance company. Two months after that, the insurance company will send the hospital a check for $180,000 and a letter saying that you will pay off the other $20,000. (Where did the other $50,000 go? Ah, that is one of the miracles of modern medicine. It just... went.) Two months after that, the hospital will send you a bill for the $20,000. Then, even in the unlikely case you are still in the US, you have two choices:
- Ignore it
- Have the following conversation with the billing department
Billing department: You are responsible for $20,000.
You: I don't have it.
Billing department: [long pause] What can you do?
You: Uh, I can pay $100 a month for five years. $6000.
Billing department: [sigh] OK.
If you are a rich guy holding out on the hospital, yeah, they will put it into Collection, which means they'll hassle you, sue you, garnishee your wages, whatever, not so much to actually get the money but pour encourager les autres.
But if you are a visitor from Outer Camelstan, the hospital knows it isn't going to get paid, they will take what they can get.
Definitely buy evacuation insurance. Hospitals are used to working on credit, and used to not getting paid. Airlines expect cash up front, and your sob story about how you need a respirator and a stretcher and a nurse will mean exactly zero to them.