Bear in mind the
wind will be spotty at best and you'll have close to 600 miles with no
fuel or services available via the Tenn-Tom, and very close to 600 miles as well, in the
Mississippi route.
Kentucky Lake will be your last facility, as I understand it, until well south in
Alabama, and Mud Island on the Miss. Cape Girardeu, MO has trucked in
fuel for
diesel onlyt and there's a 100 gallon minimum for that. If you only buy 20, you still pay for 100. I was researching a similar trip, and decided against it, myself, and will just trailer my boat down south to the Gulf, instead.