This will get the ball rolling.The first one is the hardest...gets a bit easier every deal after that!

This will also change the dynamics of your partnership, if he drops the ball and makes a poor tenant placement or doesn't handle repairs correctly losses will be his fault. 

If you can speak with confidence and show the knowledge that you already have at this stage, that should get the ball rolling and get folks to see past age.

Three days without any water or electricity during freezing temperatures. 

After a couple of low ball offers I decided to hold it as a rental. 

When I asked her if she let the water drip she said she didn't know she had to let the water drip although on the news they constantly told people to let the water drip due to the temperature dropping to the 20s for 2 days and ice was on the ground.

If that gets you nowhere you may want to contact an attorney and have them draft a letter to send to corporate, that usually gets the ball rolling.

I have a remote vacation rental so I put a smart thermostat in it so I could monitor/control temperature remotely.

I can honestly say I have done so - and had a ball along the way. 

Meanwhile, a mini split is more like 250% efficient, because it uses one unit of energy to move 2.5x as much heat.This is effected by temperature.