Drive like a grandma is perfect, much better than drive like an idiot. You probably won't need 4wd, if you do stick to 4hi and stay away from the locker button. Give yourself 3x the distance you think you'll need to stop until you've got a feel for how the truck will behave. Don't freak out the first time you hit the brakes and the ABS starts chattering at you, it's doing what it think's it's supposed to do. The ABS won't kick in if you don't lock up the tires, so think of it as a threshold warning and if it kicks in back ever so slightly off the brakes.
What tires are you running? edit - n/m, I see your sig now. I don't know how the Wardens behave in the snow, but I assume no worse than any other aggressive AT. Drive slow and careful, and most of all drive
predictable, and you and the drivers around you will be fine.