Foton404-- I think you'll find it's not a matter of digging in (my car has aggressive snow tires, and I wouldn't be without them), but rather surface area contact, on a blown or plowed, relatively low-depth surface behind the FEL or blower.
I've also found the turfs on my 2310, either pushing the FEL or blowing, have performed very well on my sloped, gravel driveway. But then, I'm not driving the tractor through deep snow; that would be a whole different ball game. In that situation, I bet my turfs would probably load up and be just about useless in about 8 feet....make sense?