I am in florida.
We bicycled ft desoto park today 4 miles. Been to myakka national park
We have biked in the ocala national park, Cape haze in englewood,parts of the pinellas trail. Most are paved a few are packed dirt like in the ocala park . We do not really time our rides. We often sit down under shady picnic areas,look at the water ( lakes, rivers ,ocean)we rest at boardwalks and watch wildlife.
For us it is more of getting out for a few hours and enjoying the great outdoors.
I would love to do A mountian biking and offroad trails trip , but florida does not have hilly areas untill you get pretty far north. Sounds like this could be a good idea for a summer trip , mountian bike trip /white water rafting combo.