There are several campgrounds around Knoxville. There is a KOA right on I-75 (Clinton/Knoxville North KOA). They have water on all year round. There is another one on I-40 East of Knoxville about 45 minutes Newport / I-40 / Smokey Mountains KOA. We've stayed at both for overnights on our way to or from Florida and South Carolina over the years.
We prefer pulling into a campground for overnights so we can have electricity. Plus, in the winter months, the Knoxville area is a good location to un-winterize the water system in the camper, fill the water tank and then when reaching our destination in either South Carolina or Florida (depending where we are going), set up is much quicker, not having to mess with the water and tanks right away.
We do the Florida or South Carolina trip the week of Christmas and the 2nd week in March. Stay 1 week and come home. In December, we use the Knoxville KOA's to winterize coming North in December.
FYI, from central Indiana, Knoxville is a good distance to drive for one day. You'll reach it there without being strung out tired. The distance is just right for one day's travel.
