Interesting concern, and i have an NHT 3.73 silverado that I just bought though have not driven in heavy snow.
I have had a 3.73 4.3l sierra with 2wd that I had zero issues with in the snow. I really doubt my new configuration will create any issues in snow as compared to a more standard rear end ratio but Im interested to see how it actually performs once the winter weather hits.
I should add, I do suspect the concerns you have would go away with a dedicated set of winter tires.