The trees are just beginning to turn here but we have had some very hot and dry weather. We are predicted to be in the upper 80's and low 90's till about the 25th. Not sure what effect it will have on the color show this year. Elkmont is a great choice but as mentioned there are no hookups. With a truck camper you will be going over Newfound Gap I presume? There is also Smokemont camp on the Cherokee N.C. side, no hookups there either.
I don't know the route you intend to take to FL but I highly recommend rt.441 all the way to FL. Keeps you off of the E-way and it avoids Atlanta. Good road all the way with nice little towns to stop in and stretch the legs. I have taken I-75 and I-95 to FL before and 441 is my choice to take now. I will never go the interstate there again. look at the map and check it out.