Is this a realistic option? Say you're an American and go to Canada or the UK (I don't know where else has universal healthcare off the top of my head, maybe nordic countries). Can you get treatment without being a citizen or owning land, do they care if it's a prior condition? I wonder how long and difficult the process would be. Also worth noting that some countries like Japan ban certain medications like Adderall, so depending on what you need, not all countries can give you the same things you can get in the US.
Yes. Quick lookup gives Argentina, Brazil, Spain, Norway, Cuba, Sweden has copays with a limit. Need to do your homework, but some have very easy residency requirements. With Europe the best bet is to get jus sanguinis citizenship if you have any ancestor who came in a boat.
The amount to move the family overseas & fund living expenses for the days/months needed to find sustainable jobs - it exceeds the amount to buy healthcare here.