I have an acquaintence that is still living in her home and has not made a mortgage payment in over five years. She is perpetually negotiating with the bank and they have drawn many red lines that have turned out to be watercolor. And they get a lot of rain in Seattle.
In many cases the banks know they can’t foreclose due to poor records or improper handling of the title.
The typical limit I’ve seen for most of those is 2-3 years. I have neighbors like that but I think the bank lets them stay because at least they are taking care of the property.
Here in Florida the empty houses degrade very quickly.