We live a few miles from Syacuse and hop on I-81 down to I-77, and over to I-95. A bit of I-26 may be in there also.
We had a old 30 ft class C towing a Jeep Renegade on a dolly. There was never an issue with the hills on that route. I would drop it out of O/D on the down hills to help keeping the speed down.
We now use our 2017, 26 ft Axis and a Honda Ridgeline, 4 door pickup, on the dolly doing the same route.
As long as you use Tow/Haul and cruise control on the one BIG hill ( Fancy Gap I-77 ), you will be fine.