I prefer bigger rather smaller myself as a rule of thumb. However, for practical reasons the bigger the vehicle usually the heavier the components are which means under heavy usage the better they stand up to the wear and tear. Also, bigger trucks usually have the ability to tackle deeper snow falls. This can be important when you are trying push back large snow piles in tight spaces or dealing with heavy drifting.So, why do you suggest such a large vehicle? How much of a difference does vehicle that weights 18,000lbs compare to a 1-ton vehicle?
Another option would be the Mercedes Benz Unimog