Florida Seasonal Camping

Thank you all so much for the tribal knowledge. We don't golf nor care much for fishing. My wife is pretty sedentary but loves to take off in the dingy to sightsee and shop. So far I have decided an RV park south of Rt 4 is a necessity and the west coast is our favorite. We just want to experience waking up every morning in Feb/Mar to bone warming temperatures and sun. We would probably like to position the coach in December and bring it back up to Maine in April. Since we have sold our company to an ESOP (employees) but I want to continue in my role as mentor and alpha salesman for a few more years, I plan to return to Maine every couple of weeks. My wife may or may not stay in Fla. while I commute.
My big unknown is the possibility of finding good quality RV parks that we can just show up to and check in. Are vacancies an issue?