DX - I've seen some of your other posts over the years. I realize that you like to do centuries - have some good equipment - have done some shorter rides - but I can't see if you've ever had the chance to do "The Big One". I suspect time is more of an issue than money - but you offer little info to go on.
I've ridden a good many miles of the route you propose - both east and west. Southern Alabama and Georgia are not particularly bicycle friendly - and I rode that stretch in February - not August. I did, however, spend a few Augusts in Alabama at my grandmother's growing up - - and she didn't have air conditioning. Lemme tell you.
The route you posted is 3000 miles. If you could do a 3000-mile route much further north that was relatively easy to start and finish - would you do so? I'm sure you could grind thru the route you posted - but if this is you first and, maybe, only cross-country ride, why pick something that is grueling if there are other possibilities?
I noticed you have posted on Mt. Hamilton before - and you have that road at the start. I'm not sure if that is essential. If you are in Reno, you can always ride the bay area almost any time. Not to mention that it will be pretty darn hot climbing in August. It's 2000 road miles from Seattle to Milwaukee - less than 800 from Muskegon to New York - with a fast ferry connector across Lake Michigan. There are some pretty direct routes with low traffic in the western section which don't add many miles over 2000. And you can ride to the Jersey Shore and catch a ferry into NYC passing right by Lady Liberty.
I've started a bike tour outside of Brunswick, Georgia after flying into Jacksonville. It's wasn't too tough - but I had a friend meet me in Brunswick. The hardest part was connecting from the airport to Greyhound - with bike, panniers, and stuff. The NYC metro would make getting back much easier. A more northerly route would still have some hot days in the Great Plains - but 5 to 10 degrees cooler than Oklahoma. The Pacific Northwest and Great Lakes states would have moderate summer temps.
Just a suggestion.
Photo - Shack Between Camden and Greenville, Alabama