Generally if a U.S. citizen works out of country tax treaties keep him from being taxed twice. Check U.S. code on how long one has to spend out of country, etc.
I’ve been in that place. Between Canada and the US, you are taxed on the place of residence.
Right now, the Canadian dollar is heading aloft and their unemployment rate is sinking like a recently unplugged toilet. Not for naught is the Conservative government’s economic policies having an effect on the overall economy...