I spent 10 years pulling PUs because my wife and I were nervous about pulling a TT on the highway. Then 7 years ago we ventured into getting a 24' TT, and that took some getting used to. Now, after considerable debate, we are venturing into the 28' territory, granted it is a light weight aluminum frame (5200 lbs dry weight). So it is only a few hundred pounds more than the 24' TT. I will have to see how our truck handles the task at hand. I would never consider getting anything bigger based on the restrictions of the tow vehicle, which is similar to yours.
I just emptied out all the stuff I had accumulated in the 24' TT, and it was enormous. There was easily 500 lbs worth of stuff in there, and that does not include the water we used to place in the tank, as well as food and drinks for each trip.
And if I remember correctly, Lynchburg VA is a pretty hilly area. Anything over 6000 lbs dry weight would be an issue, in my opinion.