they do roast potatoes in Canada... but normally of the sweet potato kind.
For thanksgiving (US) last year we had curry, I was in Puerto Rico (which is of course a US territory) with astronomers - and astronomers love indian food.
As for Canadian thanksgiving this year (which is of course earlier):
Turkey, mashed potatoes, cranberries, veg and some cheese thing (which was made for me cause I don't eat the first thing on the list). Wa yummy.