These men speak the truth! I'm an advanced rider and even I found myself somewhat bored with most of Sunshine. Both Lake Louise and Sunshine have TONS of terrain of all levels though so you'll likely have a blast at either.
I'd go wherever the snow is you'll have a blast.
Don't worry about coming from Ontario to the big hills. I grew up riding in Ontario. Moved out here last year and had the best winter on snow here. Just take it a little easy at first, the hills are a lot less "maintained" than in Ontario. Learn the runs a bit before you go and blast them!