If there are adults only, consider The Dell as a place to stay. Go to Hidden Mountain | Cabin Types | The Dell RV
and take a look. I suggest this because The Dell is located perfectly to minimize toad travel when seeing the area. For a site, with a view of the Smokies ask for lot 2615, 2601, 2603, in that order. The Dell offers peace and quiet while being a mile (no traffic mile) from the Parkway.
The SMNP has a variety of activities. East of Gatlinburg is the Sugar Land Visitors Center. Make this your first stop to get maps and advice. Some things to consider are:
Cades Cove - A driving tour through buildings of the 1800's. This is a day trip. Take water and snacks. The only place to eat is at the end of the tour at the CG store. The exit will be a left turn, to go to the restaurant make a right turn.
Clingmans Dome - A paved trail leads to the overlook. It is a steep trail.
Newfound Gap Overlook - This is right along the only main road (Rt. 441)
Roaring Fork Motor Nature Trail - The turn to get to the trail is in downtown Gatlinburg. Nice single one way paved road. Overlooks and period buildings to see. Take water and snacks.
Along the Parkway are the shows. My favorites for you to consider are:
1. Smoky Mountain Opry - Broadway quality variety show. The Dell is behind the Opry (about a mile)
2. The Wonders Of Magic - Located in the Wonderworks building. Slight of hand magician (who is in the magician's hall of fame).
3. Lumberjack Feud - Dinner show. Get past the corny story. The reason I recommend this show is the performers are professional lumber jacks performing the feats of skill they use to compete in championship lumber jack competitions.
As to roads, all are doable with a coach and toad. For me, consider returning to I40 for the trip over the mountains.