I cant speak for snow driving but i do have a lot of experience in the dirt towing with 2wd. Its all about momentum and throttle control. There is a ratio between available traction, smoothness of the road, how much youre willing to beat up the truck and trailer, and how easily you can get pulled out if you do get stuck.
If you one day skip the campground and find yourself on a dirt road, with nobody around for miles, you might be willing to attack the road a little bit faster and more rough than you would like. Just to get through and back onto hard packed dirt where you can regroup and form a plan.
We camp pretty much exclusively on sand. My 02 F250 does ok and never had to drop air pressure. I have friends who drop down to 20psi and go camp on the really soft sand with 2wd towing toyhaulers.
