Psh. All this Interior BC talk is nonsense. Yes, being further inland means less tendency for the major wet systems to make it that far, but those show up a few times a year in WA. There's real chance you'll get one, but it's small. You can minimize your exposure by sticking to higher resorts--Stevens and Crystal.
Skip super driving in a rental car and enjoy what you've got there. Part of checking out a college should involve checking out the skiing you'd be doing, right? So here's a roadtrip idea.
Check out UW. First day at Stevens, stay in Leavenworth. Second day at Stevens, stay in Leavenworth. Drive to Alpental the third morning, hit it up, drive to Green River. Two days at Crystal. Make the call if you want to go to Baker from there.