Anything from icy to knee deep. We did an event in Spain in a white out in which I managed to ride the bike about 25m and pushed/carried the rest. :-/. Organisers do try to give us snow that can be ridden but the run is often very hard work. I use trainers with a load of screws in the bottom that fit around the shape of my favourite flats (google "screw shoes"). I've used SPDs with screws when the snow is icy and Nokian spikes of course but in soft snow prefer flats because I'm faster downhill and the cleats block as soon as I have to run uphill.
