[uhftx]

I am now the proud owner of a dually,

I think it floats on the surface more so in fresh snow.

As far as the Axles dragging stopping your motion.

I believe the single axle would behave the same. If anything, the dually would allow the rear axle to lift above a single tire axle on the rear. Consider; in the snow, the larger tire foot print, the rear of the dually vs a single and the dual tire rear ends, both are the same weight. The road surface contact area of the dually is twice that of a single.

This may not be a good explanation. But its just physics with many parameters Weight, Mass, Displacement, Friction........and so on

Dual rear wheels won't help with the front digging in though.

The rear end can not dig in to the pavement as easily with dual rear wheels which causes the rear end to float more tire on the surface of the freshly fallen snow.

Just my experiences and opinion