The last time I rode in 12" of snow I was doing a lot of walking. And if I had to do it again, I would reconsider. I've ridden thru many snowstorms. But thru previous experience, I have my limits now. I think 6-8" are what I know I can handle and still ride. Its going to be an adventure, and I'll be doing a lot of handlebar wrestling getting thru that deep of snow, and I know I have to leave at least a half hour earlier than normal to make it to work on time. The worse part of riding in deep snow are the ruts from traffic. Being able to hold a steady line thru a car tire track helps a lot. But if its undisturbed then that makes it a little easier. And in those conditions I don't think having 4" tires over 2.4" tires would make that much of a difference. But I don't have any experience with 4" tires so maybe someone else can elaborate on that.