Had mine away for almost a year some years back. It was in my unheated, uninsulated garage. I filled the gas tank as full as it would go, removed the battery and put it on stands an inch off the floor. The full tank lessens the condensation. I did not put any stabilizing agent in the gas. A lot of people do so I guess I was just lucky the gas was okay.
I have not tried this but heard a bag of moth balls in the cab will deter rodents.
If the storage facility has a problem and have to evacuate I am sure the last thing they would be concerned with is moving out vehicles.

1949 Chevy 1/2-Ton
"Sedgewick"
In the Gallery
1989 Caprice