This will handle nearly all of your winter bicycling needs. Pugsley
If roads are a sheet of ice (like after freezing rain) then studded tires may work better but otherwise the wide low pressure Endomorphs on the Pugsley are incredible. And they roll better than studs if you pump them up. At 30psi my Pugsley is about as fast as my touring bike with 35mm studded tires at 75psi.
For most road conditions a touring or cyclocross bike with studded tires will handle it no problem. For bad off-road conditions or unplowed streets an agressively treaded MTB is probably better.
Craig