Cant help ya much down south or over on the west side, but around here the only place that actually stores in off months is Highland Park Fish Camp that also has the amenities you are looking for. At least in freshwater anyway. Probably a ton down south and over west by lakeland and even north around Crescent. Another is Lake Talquin Lodge, but not neessarily a storage area for off season. Highland Park has off season storage and then sites for use and slips. Good luck in your search. And yes looking way ahead is best. Heck even looking for a weekend getaway you need to plan months in advance down here anymore.