The weather will be hot in July, but will not feel quite as bad/sticky as WDW, but maybe close. I've lived about 90 minutes away for almost 17 years and have taken many one-2 day trips over, but this year am going for a week in July at the Westgate timeshare in Gatlinburg, because there's so much we haven't done (Ober Gatlinburg, Cades Cove, etc.).
Dollywood is lots, lots smaller than WDW of course, but cute and fun in its own way. Splash Country is also fun, you need to get there first thing in the morning to rush in to stake out a shady spot (hard to do). There are tons of "touristy" things to do in both Pigeon Forge/Sevierville and G'burg, just like Kissimmee/LBV. The Ripley's Aquarium is good in G'burg.
Of course, as mentioned the GSNPark is well worth seeing (unless you're used to the Western Nat'l Parks, then one day is plenty). They're optimistic, but 441 likely will not be open all the way to Cherokee from TN by July (but that should be easy to check online); there are alternate routes.
Lots and lots of outlet mall and arts and craft shopping (and if you have a scrapbooker, check out the scrapping outlet next to the store in the outlet strip across from the Governors Inn resort near
Walmart).
Use I-40 if you want to make a day trip to Asheville to visit the Biltmore Estate -- which takes a full day (leave early in the morning) -- it's more than just seeing a big, fancy house.
Haven't had much luck with food there; it's pretty much heavy, salty, fried Southern food. I think we tried Huck Finn's last time and were disappointed. Some of the food in Dollywood is better than the average in WDW, tho (at least for the cost). When we do stay over, I try to get a place with at least basic cooking facilities.
