It is very hot! But, you are from Louisiana so you can probably deal. The crowds start to drop off in mid-late August as the Southern states go back to school, but your kids are probably headed back the same time. Value season starts again for the moderates and values on August 3. It starts July 20 for the Deluxes.
We went a few years ago just before school started (August 15 -20 or thereabouts). It was very hot, but not any worse than August here. The crowds were not too bad. The Unofficial Guide has August crowd levels as mainly 6 or 7 - not too bad.