if you are looking for gnarly terrain i would say jackson is it...although it is REALLY hard to be a snowboarder there. It is just a very ski-centric mountain and a lot of the good stashes require a little extra effort as a snowboarder. But the terrain is amazing. Weather...not so much. I'm not sure what the weather was like in up in BC, but it definitely gets (and stays) cold, windy, and cloudy in Jackson. As for the lift lines there....well lets just say when I was there we would get in line for the gondola on pow days (the only way to the upper mountain-before the new tram) between 6 and 6:30 when it wouldn't open until 9 (ideally, more likely it would open around 10-10:30) and still be about 5-8 gondolas back in line. but that is part of the fun, is the locals are into their powder.
the downside of jackson is that since it is on leased land it has to close pretty early when they still have boat loads of snow.
Big Sky, Montana could be another alternative. It is one of the biggest resorts (so coming from W/B it should be sufficient) and they still have some rockin terrain.