I used 26" mtb tires that were salvaged from a bike project year ago, placing screws in every other knob, 52 screws per side. Since I only bought 200 #8-1/2" panhead screws, I had to rummage for the other 8.
I used a variable speed hand drill with a 5/64" bit to put a pilot hole in each knob from the outside. I started all of the screws from the inside with a screwdriver, then finished driving them flush with the drill at low speed. You don't want to over tighten the screws as they can strip out the knob or tangle the tire casing fabric. Don't forget: once you're done you'll need an old tube to use as a liner between the screw heads and the tube you're inflating.
It took me $7 cash and three solid hours for 208 screws. If this seems like too much work, plan ahead of the bad weather and order some studded tires from your local bike shop. I'll give you a ride report if we get more snow and ice. That might be this week or it might be next winter!