You could also go West through Chicago. I know it is what you had planned but it is possible. Welland Canal into Erie and West though the Great Lakes to Chicago and enter the river system there. You end up in Mobile Bay and the Florida Pan Handle. From there you can make the Keys and than on to your ultimate destination.
I don't know if your scheduled departure date would allow you to get South in time before it gets too cold or uncomfortable to make it, but it is a viable alternative route.
Courtney is My Hero
If a man is to be obsessed by something, I suppose a boat is as good as anything, perhaps a bit better than most - E.B. White