One big problem with driving a Vette in snow is not so much the tire (a good deep block-shaped tread design would work) but the front air dam. That dam can be easily ripped off in heavy snow on un-plowed roads. With the dam inplace it could act like a snow plow and force snow up into the radiator and effectively stop the flow of air thru the radiator and cause overheating.
Like a number of other cars, Vettes are "bottom breathers" and need some device to force cooling air up into the radiator. Without the dam, you could see abnormally high engine temps.
If you really want a "snow" tire, check out these tires at the Tire Rack.
http://www.tirerack.com/tires/tires....rce+T%2FA+KDWS
http://www.tirerack.com/tires/Spec.j...0+Asymmetrical
The BFG tire is available in a 285 but a 275 tire will work just fine on a 9.5" wide sawblade wheel.