In Greensboro area try: Greensboro Campground 1896 Trox Street Greensboro NC 27406 (ask for 50 amps) 50 amp pull thru sites are $40 per night. Raleigh does not have any campgrounds but you can find spots where I-40 and 95 connect. Durham has one RV/mobile home site available called Birchwood RV Park, 5901 Wilkins Drive, Durham NC 27705 (we stayed there for 5 months while at UNC hospital).
Outer Banks have many sites but reserve in advance this time of the year with a 40 footer. We just returned from a trip to Texas for 5 weeks and had a grand time.