Take a good look at the Holeshot H-D. While none of the classic sport quad tires are great for snow, the H-D's have agressive lugs on the sides for rutted trails and the like, which can't hurt in snow.
http://www.itptires.com/sportatv/holeshot_hd.html
Normally I run Holeshot XC's, but when I want more ground clearance I run Holeshot XCT's (maybe along with some gearing changes). When I want to ride in the snow however....I ride one of my Ranchers!