There is one on the Canadian side of the boarder at the Truck crossing called Pacific Boarder RV park. I have never stayed there in winter, but they have a nice indoor pool and hot tub. Try and not get too close to the back as the trucks crossing the boarder tend to make loud noise in the middle of the night. If Fort Langley is open year round now, that would be my #1 choice as you can have campfires there.
Good luck in your search...
2004 Newmar, Mountain Aire 40ft, DP
Langley, BC, Canada, 2011 GMC Sierra Pick UP is our toad.