(normally what happens is the unit freezes up because it can't suck in enough air because of the clogged filter. 

The freeze is coming. 

Not sure how well they will do when it is freezing outside yet.  

If they are a good tenant, I tell them about the increase and then freeze the rent.

If we weren't "required" to add heat by FHA we would never even consider doing it; except for potentially the 1 we will be occupying initially to help us get through the winter without freezing.

Sick of snow and freezing cold. 

When they get it to the correct temp (using a thermometer) food directly in front of the vents that circulate the freezer air into fridge freeze their perishables.

That's why most do accredited investors and especially at the 50 to 100k level freezing that money should have zero effect on an investor in the case of a life event.  

I've had pipes freeze in winter and burst resulting in a big utility bill. 

The banks foreclosed, investors lost everything and many sponsors went under.The next recession could be severe like that and run a risk of another bank freeze.