I am a native of the USA and I lived in Toronto (yes, Ontario, Canada) for about a decade. Because of the mounting anti-American bigotry and hatred, I eventually got the ffff out. I now live in Jackson, Mississippi.
In Canada, I found that pursuing a career, getting a date, and having a normal life (at least, in the fields and circles I was moving in) were all basically impossible, precisely because my nationality made me a persona non grata. I am glad to say I survived the extremely negative experience.
I probably would never go back, except perhaps to impose even greater cultural imperialism than already exists.
No, seriously, if the money were right, and I were more "established" I might return -- there are a lot of advantages. But as a beginner, it was miserable. If I had a nickel for every time someone said, "You stupid Americans. But not you. You're different." Or told that dumb (false) story about someone driving across the border at Buffalo or Fort Erie in July to go skiing. "And do we have to watch for the polar bears on the streets?"
Try saying, "But not you. You're different," when the preceding sentence uses "Ethiopian" or "Jew," and you'll see how offensive it can be to the group you're talking about. Canada has a problem -- a huge inferiority complex. It's not unreasonable for them to be defensive -- the USA is culturally expansionistic and overpowering, and many things legitimately Canadian and valuable are getting washed out by the gross middle-ization and Wal-Martification we propound upon them. Nevertheless, I'm glad to be out ...