If I pull out my crystal ball, I would say this is probably going to be a horrible time to go. The lower level APs are unblocked in mid-August, and those reservations have quickly been taken. You get the worst of all three worlds: APs are unblocked, many kids still not in school, and the weather is challenging (hot).
If Labor Day is your absolute final last day available, I would recommend the week leading up to Labor Day weekend as more kids are back in school.
If you're flexible, the week immediately after Labor Day (like, Tuesday-Friday) has tended to be an even better period of time. However, you risk the MSEP being done (historically has ended in August, but these aren't typical times anymore).
Do note that the Haunted Mansion will probably be down in the 2nd half of August for the holiday overlay installation, and will return in time for the start of Halloween festivities starting September 2.