Some of the above talk reminds me of certain physics, the facts of which probably go something like this: Given the same weight on the rear wheels between two different truck chassis, the one with duallies in the rear has better flotation on soft surfaces than the one with single tires in the rear - due to greater rubber surface area carrying the same weight.
What this means in practice - I don't know - as I'd never try to travel any road like Bear Camp Road in snowy times of the year in an RV. However, I have read several times in these forums that Class C motorhome owners with DRW drive in the rear have traveled CAREFULLY AND SLOWLY on roads in the winter with no real problems.
Just for fun, watch this video all the way through to see what's really possible with an RV in extreme mud on the way to ... or coming from ... boondock camping:
http://www.youtube.com/watch?gl=US&client=mv-google&hl=en&v=eqL2qZ3YsMg&rl=yes&feature=related&nomobile=1