You should dedicate a week or so if possible as the up state of SC and also the neighboring area in NC have a good 20 waterfalls all within 2-3 hrs driving distance. A number of the falls here are GIGANTIC. There are two that I know that are 300+ feet. One of those is the largest fall east of the Mississippi (Whitewater falls). The best autumn shots down here (in the mountains) are had in mid to late October. Its definitely worth the trip.
Dave.