Any ideas on how to get my TT from Wisconsin to Florida?

Are you saying it`s only giving you issues on hills or inclines? how is it on flat highways?
Even with a 3.42 gear you should still not have any issue towing it!
When you had the tune up done did they replace the fuel filter? it could be partially plugged and not delivering enough fuel under load!
Are you letting the engine rev on the hills or are you backing off because your worried about it reving to high?!