1. Soulianis didn't take the Mississippi all the way (which the OP implies), ending at New Orleans. They took the Mississippi to the Ohio River to Tennessee River to Tenn-Tom Waterway to Tombigbee / Black Warrior river to Mobile, AL.
2. They did not do it last year. (Fall of 2018.) The videos they are putting out imply they are 3-ish months behind. They are actually a year and 3 months behind. Go to their FaceBook page and go back to summer 2018. They were back from the Bahamas and had Soulianis on the hard in Fort Meyers, FL, for a new bottom.
Timbuctoo, if you come the route Soulianis did as I just described, contact me when you get near the Ohio River. We're familiar with the North ends of Kentucky Lake (Tennessee River) and Lake Barkley (Cumberland River) as that is where we keep our boat and we will be southbound to Tampa Bay from there ourselves come fall.
At the north end here, there are several marinas (4?). IMHO, the two nicest full service marinas, practically back to back, are Lighthouse Landing on the east side of Kentucky Lake and Green Turtle Bay on the west side of Lake Barkley. Between them is the tiny town of Grand Rivers.
There are several marinas on each lake further south, but going further south on Lake Barkley will take you out of your way. There are hundreds of coves to anchor in, but TVA just started to lower the water level from summer pool. Over the next 2 or 3 months the water will go down 4 feet to winter pool. By October your 8' draft will keep you in the channel a lot.