It depends on how it'll be used. If it's for a sort of Rally Pack (something that has been talked about before) with proper studded tyres on snow covered gravel then I'm all for it. If it's just a different weather condition (like dusk, daylight, rain, snow) then I don't think it makes sense on a tarmac track. I've seen some snow driving (Best Motoring driving Subarus, Evos and Skylines on snow and one of the Porsche engineers driving a 993 or 996 Carrera on a snowy Nurburgring) but I don't see it making for good racing.