August is the worst time to do this in the deep South. The humidity and heat will be very bad. Long days in the saddle on days with high humidity are, IMHO, not a great combination. I grew up in Louisiana and I respect the weather there.

If you are going to do this trip, I'd get a camel back and keep it full of ice so that at least you are drinking cold water all the time. Also I'd get a good lighting system, wake up early and get my mileage done before 12. That way you can spend the afternoon in a hotel swimming pool.