For $2000, the price of many optional all-wheel drive systems, it's much cheaper to simply rent an all-wheel drive vehicle if you decided to go skiing, etc.
Furthermore, if you learned at all to drive on snow you could easily handle a front-driver in ski country. In Denver, we see front- and rear-drive cars all the time wearing ski racks. I have a great picture of an E34 (1992ish) BMW M5 with ski racks on it that I took as the vehicle was doing 80mph (in a 55) coming down from the Colorado mountains.
Check this out - all-wheel drive system prices on some compact SUVs:
Ford Escape: $1750
Honda CR-V: $1200
Hyundai Santa Fe: $1500
Kia Sportage: $1500
Mazda Tribute: $1500
Toyota RAV4: $1400
Meanwhile, Hertz's rate for an all-wheel drive-equipped compact SUV is around $45 a day. See what I mean?