I have met a few of the long-timers.
I also have a few family members who do the long-term visit to Florida (Dec-Mar) not at the Fort but at other places in Florida.
Disney has cracked down in the past years to only allow folks long-term who deserve to be there. There have been abuses of special discounts for short-term stays that were applied to long-term stays (through multiple reservations) that Disney has addressed. Those threads still exist but some posts have been hidden/removed to protect the guilty.
One interesting aspect to me are the rules for becoming a legal Florida resident. For those that don't know, Florida has no state income tax for legal residents. That state income tax amount, hypothetically, could be used to help offset the cost for a long-term stay. Cash outflow is cash outflow. You could pay it for income tax to your home state. Or you could stay one more night and pay it to Disney for many nights at the Fort. (FOR THE RECORD I do NOT give Financial nor Legal Advice).
I knew a guy who used the "Florida legal resident" rules, although he was not a full-timer, to have a Florida Drivers License with the Fort Wilderness street address on his Driver's License. Obviously that requires a certain level of commitment.
Not that I would do it (or would WANT to do it). But for those that spend a SIGNIFICANT amount of time away from home, there are ways to justify it on paper.
Me, I love my home state and my parents (and my in-laws the out-laws) are still kickin' strong so I have reason to be a Bammer. But there is more to it than just justifying the daily rack rate for a site in the fall-winter-spring months.
Bama Ed
PS - FOR THE RECORD: Always follow the law.