UBC seem to have a really active ski and board club. Plus Vancouver is a really decent city. In terms of proximity to skiing, you've got Grouse, Cypress and Seymour all within a hours drive from the UBC area. Beyond that you've got Whistler which is 2 hours from downtown and Baker too, if you want to deal with crossing the border.
As for the Okanagan campus, there's skiing nearby, but it's very average. The Okanagan is a semi-arid desert so the seasons are pretty short and the terrain isn't that interesting. Although the snow is unbelievably light, it's certainly the lightest stuff I've ever skied. I can't really comment on what it's like spending time in Kelowna, but driving through there on two separate occasions there didn't seem to be too much going on.