I can understand some of these last bitter days not wanting to
venture outdoors, but for the most part the winter can be some of
the best rides of the season. You don't necessarily need studded
tires although they help. The hardest part is to monitor the
conditions. If the snow is packed - go for it. If there's a couple
inches of fluffy stuff - go for it. If it's slushy snow or there's
more than 3" it's going to be rough. When in doubt hit the road and
get some miles in. I'll ride all winter long and I'll be out even
in these conditions. Just find a system of layering clothing so
that you'll stay warm.

Here's what I wear for winter rides:

sleeveless base layer
long sleeve jersey
wind jacket
bib shorts with leg warmers
thermal tights
shoe covers
lobster gloves
thin ski hat

If it gets into the lower teens or single digits I'll throw on an
extra layer of tights and a different jacket but that's it. Oh and
don't underestimate the power of those chemical toe warmers. It's
all good!!!

Ryan