If riding on trails with packed snow, then you want fat tires -- four inches wide or wider. Framed Bikes has some good sale pricing right now.

If your target trails are groomed for fat tire biking, then for sure you want fat tires lest you face the ire of your fellow riders who won't like the ruts left by anything skinnier.

Are you just wanting to commute and ride around town in the snow? I live near Lake Superior and have been having good luck with some 700c x 38 mm Gravdals from 45NRTH for just riding around town for errands and exercise during winter. You could run a set of those on your ToughRoad.