We go to PF and Gatlinburg often - it's about 2 1/2 hrs away from us. I have several recommendations, but it's according to what you want.
If you want a full-service campground in Gatlinburg, try Twin Creek, which is just outside of the downtown area.
If you want a full-service campground in Pigeon Forge, try Pine Mtn RV Park (our favorite), which has a year-round pool to use.
If you want to be out of the main areas, but still have FHU, try Smoky Bear in Cosby. Owners are on-site and care for it.
If you want limited services, Elkmont is great, but may be closed for the year, I'm not sure.
Just so you know, there is lots of traffic in Gatlinburg and Pigeon Forge, even after the fires, but they sure do want your business (money).
Pine Mountain is at the lower end of Pigeon Forge, closer to Gatlinburg and about 1/2 mile from the bypass that will take you up into the GSMNP to the Sugarland Welcome Center.