Here I see a link to Drive BC info
Check the links lower down on the page it will give you tire requirements to for RV's as well as road maps showing which ones require winter tires, and other "stuff"
Drive BC LinksI live on the west side of Kootenay Pass ( Salmo / Creston) one of the highest mountain passes open year round in Canada . The RCMP have turned people around from time to time in bad weather conditions ( snow) because they don't have correct tires on their vehicles, I have wintnessed it.
I'm not saying they will turn you around on your trip,at that time of year and the chances are slim, however it has been done under extreme weather conditions around here, so just keep an eye on the weather conditions and Hwy cams formthe route you take.
Hwy 1 would be the best route to the coast anytime of the year in my opinion.
Soup..