Sometimes people don't expect to see a cyclist out in the winter, so have a good torch, rear lights, blinkies, I was at a junction last winter, everyone came to a stop and this motorist did not see me, worked out okay but I waited for them to stop, then I proceeded and they started up but stopped in time, they must not have seen me, so again, overly cautious. Once, there was a lot of snow and sometimes, you'll have people, mainly kids who want to see how their car will fishtail and the like in the snow in areas I go for shortcuts home, industrial areas through car parks, they don't expect to see a cyclist either, so with warmly protected feet, I'm often ready to hop off the bike and drag it out of the way if need be. Hasn't happened but nothing to be at risk about either. Which comes to another thing, I certainly don't use clip-in pedals in the winter. Some do, if you're comfortable, go for it.