For heavy snow and other treacherous terrain, I like my 26inch mountain bike for it's stability and wider tires. For roads with less snow or just wet roads, my 'cross bike works well also. I mix and match depending on conditions.

Also you probably wont be able to mount cyclocross tires on your road bike; the tires are too wide to fit through your brake calipers and chainstay. Cyclocross frames use either cantalever or disc brakes so the tires clear.