We stay at Blueberry Hill RV Resort
in Bushnell, which is not too far from Brooksville. We got a site there last year at the last minute for Dec. thru March. We did have to change sites part way through our stay, but that was no big deal. We made reservations for this year before we left last year so we now have the same site for the whole stay.
Don't know what your price range is, but Blueberry is $525 a month for stays of less than 2 months ($475 a month plus electric for 2 to 5 months). Sites in front are paved pull-throughs, but they are a little narrow. Sites in back are grass back-ins, but they are very spacious. If you're interested, give them a call to see what they might have open.
Otherwise, an internet search like GaryKD suggests is probably your best bet. There are a lot of campgrounds in that general area.