It depends on if you need air access or not. Fernie is fairly close to Calgary and the airport. Castlegar (cheaper than Nelson, better weather) is a three-hour drive from Spokane, WA.
If you want to be doing travel back and forth it is significantly cheaper to fly out of Spokane than any Canadian city, especially in the mountains of BC where you will pay through the nose to be rerouted through Calgary/Vancouver. Also the issue with getting into the smaller regional Airports (esp. Castlegar)
Grandforks is nice, has the most sunshine days out of anywhere in BC and close to Christina Lake, would be good if you were location independent as far as work goes, have to drive a bit further for mountain activities if that is super important.
Fernie might have some deals available due to the oil industry tanking, It's a charming mountain community.
Valemount is small and pretty. We lived in Mackenzie for a few years and found the lack of services and family in the North a bit too much for us.
We have found Castlegar to offer everything we wanted without having to make any compromises. It is 1/2 way between the Ski hills in Nelson and Rossland, has an amazing riverfront park system, lots of hiking and mountaineering options, the Arrow lakes has enough amenities and is close enough o a big US city.
They all have super different vibes though, so it would probably just be a matter of where you feel most comfortable. Come for a visit!
