Is this during summer? Are you coming up I-85? If so, I have a few suggestions in NC. There is a big waterpark in Greensboro called Emerald Pointe which is nice. Or, close to Salisbury, there is a big ranch where you can ride in horse drawn wagons and feed all kinds of animals from potbellied pigs to water buffalo and giraffes. It is called the Lazy 5 Ranch. Or north, there is the NC Museum of Life and Science in Durham. It has great outdoor, as well as indoor exhibits for kids, but is enjoyable for adults as well.
Marsha
Emerald Pointe is a much nicer park than Carowinds. Of course, it is ONLY a water park -- no coasters or other rides. Look for discount coupons; I don't know off the top of my head where to get them, but I hear about discounts on the radio all the time.
The Lazy 5 is fun, but it's about a two-hour activity. It also isn't active, which is probably what the OP wants after having the kids in the car for hours. You ride through a "family zoo" and see giraffes, a rhino, deer, antelope and other assorted creatures. They cater to school field trips. If you go with a group and plan ahead, you'll get to ride in a horse-drawn wagon; if you just show up, you'll drive through in your own car.
If you like zoos, Columbia, SC has Riverbanks Zoo which also has a botanical garden. Near Spartanburg, SC, there is Hollywild Animal Park where you can do a "safari ride.' They both have websites.
There is also a Great Wolf Lodge in Concord, NC - near a good outlet mall and not far from Lowes Motor Speedway - where you can take a tour and even ride around the track in a van to victory lane. Charlotte is a lot of fun with a lot of different things to do.
Charleston, SC would be a nice stop also. Lots to do there and educational too.
Haven't been to Carowinds in a long time, but I do remember that it was HOT and miserable and I love coasters! But, have never been to the water park there.
We love the Columbia Zoo. It's a small-ish zoo and very walk-able. There's also a botanical garden attached. They have a great "Lights at the Zoo" event at Christmas.
The Great Wolf Lodge is great (but pricey) and has a MagiQuest game inside. The restaurant is pretty good and not too expensive.
Charleston's great. Their aquarium is wonderful -- expect a half day there -- and theres' the USS Yorktown (you can actually spend the night on it). If you want a hotel right next to the Yorktown, try the Hilton. You can literally walk over. You might also think about a ghost tour after dark.
Savannah is also a wonderful old Southern city, but given that you're looking for a stop on a driving trip, I'd suggest that you choose Charleston. Why? Simply because Savannah is much farther off the interstate. They do, however, have better food in Savannah.
Concord Mills Mall bills itself as an "outlet mall", but don't assume that means low prices. They sell regular, new merchandise -- not clearance stuff, not seconds,
not outlet prices.