We know that you are going to be as far east a Nashville... and we all know that it is going to be very hot.
I have been thinking about your return trip... suggesting a big loop.
I see your boat... understand your love of water
One of my favorite places is
New River Gorge in West Virginia. The New River in one of the top whitewater rivers in the world... and safe enough for familys. I've had my grand children on it. There are commercial outfitters that have all day trips... a lot of class 5 rapids (eastern measure) andit would be a chance for you to put the family in a raft, while you paddle your boat nearby. It is just north of Beckley, WV.
Then, consider traveling north to Niagria Falls (if you have passports... the Canadians own the scenic falls)
That would put you as far north as possible for your return trip across country. Lots to see up theit too.
Chet