Get to know your neighbors in Florida and talk with some of the locals at the bike shops there. They'll be able to tell you more real world stuff.

However I wouldn't worry much about it. Just keep the bike clean and lube the stuff that needs lube. Your steel bike might get some surface rust inside the tubes and any bare spots where paint is chipped off or scratched. However it won't cause any issue unless you don't give it any attention for many years.

All my old steel bikes I had for 30 and 40 years had rust inside the tubes almost from the start. It never progressed beyond just surface rust. Perhaps to some extent the surface rust actually acts to protect it.