That is a really good question. I actually thought we had an article on it, from a few years ago, but I can't find it. I've commissioned one.
In the meantime I'm sorry I cannot answer your question. There are many private health care plans that provide supplemental services to OHIP which probably also offer full coverage plans, but I don't know how affordable they are.
Travel insurance is an option too, but I suspect it is way more money.