At our private lake, they have permanent site yearly camping fees of $610 and the camping runs from 4/1-10/31 when they turn the water off. You have to own a lot to have access to the permanent campsites. The lots cost between $1,500 (non buildable)-$50,000 (lake front). Vacant lots have an annual association dues of $336.
If you had an RV, you could be there from April 1- October 31 (7 months) for $950. That works out to $135/month. To me that seems pretty cheap considering it includes access to the lake, pool, tennis courts, club house, some summer activities, a shower facility, and electricity. There's no sewer hookups, but there is a dump area for sewer.
Then you can leave and go somewhere warm for the winter....