If you get a good amount of snow, and you want to be sure you don't get stuck, then get a set (yes, all 4) of real snow tires. After you use real snow tires, you'll know that all-season tires just don't work nearly as well when there's actually snow on the road.

AWD just gets you going fast enough in the snow so you can really get in trouble. EVERY car on the road has all-wheel brakes. AWD will not give you any advantage when it comes to stopping.