NH up to Canada in Sept.

After Labor Day you'll have no problems getting sites unless it's foliage season on the weekends. There is so much to see and do it's hard to make a recommendation. I would head North to the White Mountains from Loudon. Depending on the size of your rig you could either stay in U.S. Forest Service C.G. or private. Any of the NH KOA's are great albeit pricey. Branch Brook in Campton, NH offers large private sites although the CG itself is rundown. Make sure you go by the Mt Washington Hotel and Cog Railway and perhaps do the Mt Washington Auto Rd if it's a nice day. I would make Bar Harbor, Me and Acadia National Park a high priority. Many good CG's up there where you can camp right on or near the ocean. It's all good, you really can't go wrong. Use RV park reviews and please post to it as you visit the CG's.