Weather patterns in the Canadian Rockies can change rapidly, be extreme at either end of the spectrum and very hard to forecast. While travelling in the mountains or driving here you should be prepared to deal with any type of weather, regardless of the forecast.
It is not uncommon to experience temperatures in the -25C to -35C range and during winter temperatures down to -50C do happen at some point most seasons. Cold spells can happen suddenly and be short-lived or they can sit for weeks or even over a month. If planning a mid-winter camping trip it is important to plan for these temperatures and to use tested gear that you can rely on.
It is also not uncommon to have warm swings, even mid-winter. Although this is less of an issue for gear prep, you should take careful note on the changes this can produce in the snow pack.
Avalanche Canada Forecast
Windy.com live map, 2000m ASL
Windy.com live map, 3000m ASL