I can't imagine there would be a problem as long as you have a visa to be in the US for that period of time and a way to have the follow-up done in Canada. Since the recipient's insurance pays for everything, that shouldn't be an issue, unless the Canadian health plan would refuse to cover follow-up but I can't imagine that, either.
BTW, I am type A and my recipient was type O. I have blood type A2 (most people are A1) which contains a lower level of whatever O reacts to, so since my recipient had low levels of whatever reacts to it (terrible explanation, I know) we could do an ABO incompatible transplant. I don't think these are done everywhere, though, but just in case, you should find out if you are A1 or A2.
Also, my recipient happens to be a Canadian citizen who is living in the US on a work visa. There weren't any issues with that (of course, he has private American health insurance).
I don't think I've helped much, but there you go.
Welcome!