I'm not sure where you are starting from. I just do not know NC. I would work my way over to I-81 then follow it up to Harrisburg, PA. Pick up Rt 15N in Harrisburg up to I-99, I-86, I-390, Rt 63, Rt 20W, Rt77, Rt 33, Rt78, I-90, I-290, go either Rt 62 or I-190 into the falls depending on where you are headed for. Most of the interstates have a parallel highway that is the old road so reasonable accessible but through town instead of around it. Pennsylvania has been steadily making 15 into a superslab with the old 15 still there. Ditto NY. The Buffalo bypass has one small toll and a toll one way over the Grand Island Bridge. There is a KOA on Grand Island and a state park north of the falls depending on what you want. The area you will be moving through has history back to before the Revolution and side trips all along the route. It does bypass the major urbanized areas.