always be prepared like everyone has posted,
but what's one hour from home in winter? 10-15 miles? ditch the bike and start double timing it home or to someplace warm. you'll be there in a few more hours.
if you have to shelter in place, find evergreen boughs or dry forest material (moss under snow, leaves) and add dead air space under clothes.
When it's really cold, you'll be warmer inside the snow. find a treewell drift, and dig in.