To the Original Poster...
Choose between Lake Louise or Sunshine. I would recommend Louise. Sunshine is spread out with flat areas, and you need to know your way to the short-steep stashes that exist there. Sunshine does get much more snow though and it's 30 min closer.
If you guys are beginner/intermediate, the flat areas on Sunshine might be the death of you, we saw lots of boarders unbinding and walking. If you are all strong riders, you'll have no problem holding enough speed to clear the flat spots.
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!