Define "skinny" tire please. While I agree that trying to drive through snow with 14" wide tires would be crazy, I'm curious about your theory.
My personal experience and opinion...I currently run a 295/65/20 tire which is 35x11.5x20. I have had no problems at all with traction. With today's tire technology combined with the weight of these trucks outfitted with plows, salters, back blades can easily weigh 10k. Theres no lack of traction. Not to mention, you're driving where you have already plowed most of the time so wouldn't you want more tire in contact with the pavement for better traction? I know there's a line but I think the "tall, skinny tire" is an old way of thinking.