Preppers’ PING!!
This is a great link to more about this shelter including 360 pictures of much of it.
I have a house in Maine for sale, a great getaway. Similar price.
Great spot for a wingding
A place like that in Florida without active air conditioning would be a nightmare.
Probably has mold on the walls and bugs galore.
I could not find a story that indicated the sq. footage. If it is big enough they could turn it in to a data center like this one:
http://www.westlandbunker.com/
This is a little frustrating, because the emphasis here was on a basic bomb shelter, not one that was efficient, with low maintenance, and designed to maximize water, sewage and energy efficiency.
As such, restoring it to functionality and endless maintenance would be just prohibitively expensive. It would cost less and you would get a heck of a lot more if you built from scratch.
Not impossible, as many places already have abandoned hard rock mine shafts, vertical and horizontal. If they have survived for 50 years without evidencing any problems, it will probably be a good place to build.