However, nonqualified use does not include any period of such use that occurs (1) any time during the five-year period ending on the date of the sale that occurs after the last day of use as a principal residence, or (2) any time (up to two years) that the taxpayer is temporarily absent due to a change in place of employment, health, or unforeseen circumstances. 

Brad,I checked on our markets for Dwelling Fire Policies (most common form used for 1-4 family rentals). 

Owner is an aged widower man in failing health that NEEDS to move to a nursing home or assisted living facility. 

We all insure our health, auto, homes from fire and theft - most want to avoid paying for flooding coverage.

This is more common then you think.

At least one of us should be able to continue working remotely (how do others get health insurance without working a normal job?)

These tips can also be used to achieve success in other areas of your life such as health, relationships, etc.1  Positive Mental AttitudeThe only thing in life you have control over is your mind.

Is a 50-50 split of ownership common for something like this?

Trying to mitigate against common pitfalls but I think a good lease should do it.

The rent covers mortgage+tax+common charges+insurance.