Since you are currently a Florida resident, there is little motivation for you to change your legal residence, since you are already in a state that is popular with fulltimers as a residence. RV registration fees are very low, no state income tax or personal property tax, no special driving license needed for large RVs, and flexible government policies for part-time residents (FL is used to dealing with folks who do not physically reside in the state year around). Sales taxes about average (low compared to the northeast, though) if you buy a new RV there. You would want to change your address away from the Ft Lauderdale area, though. Vehicle insurance is relatively high in Florida (compared to western states) and the south Florida metro areas are the worst in the state. Your vehicle insurance would drop substantially if you use an address in central or northern Florida. Our home base is near Ocala, though we used to live in Boca Raton (1977-1993).
Other good choices are Texas and South Dakota.
If you do not take any overt action to establish residency elsewhere, your Florida residency will remain in effect indefinitely. It is not necessary to own property in a state to be considered a legal resident (domicile) and in fact, merely owning property there does not in itself make you a resident. Domicile or legal residency is a complex subject that you will need to learn more about if you decide to make a change - feel free to ask further questions if you want to go that route.