KY and TN can still get pretty nippy in April (if in tents). With a camper or RV, never mind.
Enjoy.
P.S. I could never get enough people to commit in advance, but I always thought it would be cool to rent a houseboat on Kentucky Lake or even in MO or TN.
They have some really nice boats with a hot tub on top, a water slide, AC, big screens, full kitchen... Then you rent or bring a smaller boat and or jet skis to tow along and anchor and camp wherever. Many bigger lakes like Kentucky or Lake in the Ozarks also have nice restaurants, casinos, comedy clubs, etc. you can pull right up to.
Here's an example. The first thing that came up on a google search:
http://www.houseboating.org/58-foot-Lakeview-Yacht-Houseboat