I have a higher water content in my mix, like 60% water as that conducts heat away better than the antifreeze. I don't think you have to worry about -40F or something in Florida. You can also try to take a waterhose from behind and flush those dead insects out from the radiator.
I would let it idle and see how high it goes. Does the radiator get hot evenly, do you see/feel the coolant flowing through the reservoir? Do the aux. fans kick in and does the fan actually run faster when it is supposed to (107 C I believe).
The fan clutch seems like a good suspect,though, if it gets that high.