Hi Ronnie and Cheryl
I have to agree with everything that Steve said. We have started snow birding in South Florida each winter. With us, money is a big issue and the prices on the keys are high. We stay on the mainland at the entrance to the Keys for less than half the price of the Keys. We have Everglades National Park to the west, Biscayne National Park to the east, and Miami an hour to the north. We tow our Saturn Ion and we frequently use it go to lunch in Key Largo and we take several -long- day trips to Key West (2 1/2 hours each way) during our stay. Steve's suggestion of spending some time in the upper keys and then relocating to the lower keys is excellent if you can do it. However, be careful to check lot size. Many of the parks I've seen on the keys have extremely tight sites. Good luck, enjoy!
Jim