Around thirty-five years ago, give or take, here in Saskatchewan we had a movement (two guys, as far as I know) called the Unionest Party (no, that is not a typo) which wanted, apparently, to allow the U.S. to join us. So, give us your loyalists, your royalists, your fugitive slaves, your draft dodgers... and anybody else who's yearning to breath free.
The only drawback I can think of is the average daytime temperature of minus a million.