I've never been to Whistler but I can tell you a little bit about Banff:
- Lots of accommodation, should be cheaper in November as it's off-season. The cream of the crop is the Banff Springs Hotel.
- Very scenic with lots of attractions close by - Sulphur Mountain gondola, Lake Louise, Columbia Icefield, hiking trails, hot springs.
- Can be chilly in November from what I've heard.
- Lake Louise ski resort is scheduled to open November 9, weather permitting. Also Sunshine Village could be open.
- Banff is very touristy - main drag is full of tourist shops with all the standard stuff
- Very easy to get to from Calgary.
Hope this helps a bit.