We have winter-camped for the past 3yrs but in Mass, not B.C. I've travelled to southern BC, and I believe winters there are much milder, though much more rain than we get here in New England.
You will find drafts/air leaks you never knew you had, but easy enough to deal with. Electric heaters vs. furnace is always an interesting question, and it depends on the cost of propane and elect where you're staying. The parks we've wintered in both delivered propane to the site, and provided a 100lb tank. Elec was metered. We used a combination of heat sources, and I think running the furnace for an hour or two each morning and evening helps keep the humidity down in the coach. We'd run the electrics overnight, where we enjoy a cool bedroom anyway. You'll want to keep an eye out for Mickey and Minnie...I put bait in my belly pans and used 2 low wattage electric "buzzers" (rodent repellers). No idea if they're effective, but we never had a problem doing that.
You'll need to find a way to deal with water. Both parks we've used had 1 or more faucets that were available for jugs, etc.
AND...we absolutely love winter camping
๐ Every friday/sat night, us and the others that stayed there would gather around someone's campfire, and have a great time. Usually someone would have an outdoor TV for sports on Sundays, and it's just been a lot of fun meeting new people
๐Jim
2005 Pace Arrow 36D
Very Understanding Wife
1 Boxer ๐
3 Maine Coon cats