I think that is do-able plan. There are lots of things for the kids to do in the Charlotte area while you go to convention. Not sure where the Pirate cove Cg is at NC coast. But again lots of things to do at the coast of NC in the summer. You plan to travel while the kids will be basically sleeping which is good. Make sure you have DVDs or some type of playable devices to make sure you dont get that ARE WE THERE YET? We used to drive to FL always at night when our 3 were younger. Now they are all grow up. You plan to do things with them on the way down that will work. You have a good plan and if you allow for a few unexpected detours you should be fine.
Now as with all my posts this is JMHO.
randy in NC.
