Drive over and put in at Chattanooga and cruise up and do it in reverse!
Either way, instead of continuing west of Paducah, after enjoying the Paducah wharf area at the transient boat dock for a few hours, cruise down the TN River to Land Between the Lakes NRA for a couple or so days, cross the Barkley Canal, lock through to the Cumberland River and cruise downstream to rejoin the Ohio at Smithland. Nice spot, lots of nice marinas on both Kentucky and Barkley Lakes and some wilderness shoreside activities.
I would love to extend a loop trip to cruise the full length of both the Tennessee and Ohio Rivers, both places are near and dear to my heart from boating adventures with my family in my youth. The locking experience alongside pushers and barges and large yachts, as a grade schooler, loom large in my memories. Alas, my spouse is less enthusiastic.