You could buy fixers ideally suited for air B&B.  

So there are relatively few natural gas pipelines up in that part of the country vs the midwest.In moderate climates, or mainly air conditioning areas, ie Florida and some of the moderate winter states like TN, Florida, the Carolinas etc there was a push to install heat pumps.  

Use an air tight lease that addresses what happens in the case of her death.

Hello BP,My name is Dylan Stone and I'm a former oil rig worker turned licensed realtor from Los Angeles county (yes we have oilfields here) I made the decision to get into real estate after being laid off from my oilfield job and after reading numerous books I figured "If I can work 12 hours a day doing back breaking and dangerous work for somebody else, why not work for myself in an air conditioned office" haha.

I want to replace my recessed lighting with LED retrofit kits as part of the air sealing I'm doing before insulating my attic.

I have a friend who's pushing hard for us to visit this summer for his birthday- and...I made the mistake of looking at Air B&B options there. 

Or even try to manage it as an air B&B type rental. 

Water is bad enough, but heat and air are too big of variables.

My forced air furnaces don't have central AC, but once each year I open up the main compartment door and vacuum out any dust/debris.

If you want to take the chance on Miami Beach, I would recommend speaking with a realtor that knows Miami Beach really well as they will know which ones are able to run as Air BnB rentals.