My wheels get quite warm after driving for a while. Consider that you are slowing down close to 5000lbs plus some of your tow vehicles weight by 4 drum brakes with relatively poor heat dissipation. I would check the brake adjustment as it is described in past threads, to be safe, especially after the shoes have seated a little by now. But if they are not tight and your bearings are not too tight,then I would say that the heat is normal. Oh, and check your air pressure. Tires and wheels get very hot when underinflated. As I said, my wheels and hubs get very warm after coming off a freeway run, and after driving around town a bit, and my bearings and brakes are adjusted just fine. Plus we're having 90 degree weather. I totally understand your concern with going to Tahoe, but if everything was done right, you should not have to worry.
Have a safe trip!