In the OPs case or anyone else for that matter, winter driving lightly loaded, just run the outer dual only to increase tire pressure. No it won’t ruin anything and won’t even look (too) weird like running the inner dual.
Used to do this all the time on light duty dually pickup plow trucks. Only downside is wearing down a pair of the rears more than the other, although N Canada, winter, tire wear should be almost non existent. Or a cheap set of rims with some winter stud tires would be even better.
At a minimum, lower the pressure in the duals to the absolute min you can. No more than 20 psi in the rears will help traction on an empty or lightly loaded dually.
