If your entry and/or exit point for the Canadian Rockies will be Calgary, you will find pertinent information on the Inside Banff : Arriving & Departing page here at TripAdvisor. 

The Inside Vancouver : Getting to the Canadian Rockies page here at TripAdvisor explains the traveler's options for getting from Vancouver to the Canadian Rockies -- or conversely from the Canadian Rockies to Vancouver.

Here is an up to date Road Conditions Report for Canada's Rocky Mountain National Parks.