We have found tracks in the snow on 2 or 3 occasions, but they are really rare in winter, why I don't know. They were always the tracks of a lone individual. Maybe a loner male, or a hunter out and about while the rest of the clan is holed up somewhere.
They also may travel when they are sure the tracks will be coverred soon by falling snow whenever possible.
Sometimes we would find one or two good tracks, but no tracks leading to or from them. Another time snowmobiling, we found a long track way through a willow swamp, just off some railroad tracks. Minutes fresh, so we probably surprised it. It was still snowing hard, so they would have been obliterated in a few minutes, if we hadn't stumbled onto them. These tracks had melted snow in the bottom, turning to ice, that told me their body temp is much higher than ours. So I agree, they aren't bothered by the cold as much.