If the rental property is in Minnesota, see below:From dmv.org about Minnesota:If you’re new to Minnesota and your current out-of-state registration is still valid, you will have 60 days to register your car with the MN Driver and Vehicle Services (DVS) once you establish residency.If your out-of-state registration will be expiring soon, you must register your car with the DVS before it does so.If your out-of-state registration has already expired or if you had to surrender your plates after leaving the state, you must register your car BEFORE you drive it in Minnesota.Exception:If you’re a non-resident student or member of the military located in Minnesota but claim residency in another state, you do not have to register your car with the MN DVS as long as your registration remains current with your home state.

(Although I might surrender)So far, it has been a smooth ride......Except today.

It is 95$ to surrender a cat to the county.Trap neuter return cost somewhere around 50$/cat.Trap cost 70$ on amazon, you can always drop of a trapped cat to a shelter and leave.Pick your poison from above.

He had no idea what the legal repercussions of not formally surrendering the keys were.

All occupants must remove personal possessions and surrender the premises to no later than May 31, 2018. 

You shall be entitled to the return of the balance of the security deposit after the Premises have been vacated and inspected by us and found to be in good condition, subject to normal wear and tear, and all keys have been surrendered.

I would have thrown up the white flag of surrender years ago without more of a goal than making money.That said, like @James Wise has pointed out so illustratively twice, I no longer 'rescue' single mom's from the half-way house.  

In chapter 7 your friend could surrender the house and discharge her liability for the deficiency, but that's only if she qualifies for chapter 7 and if bankruptcy is appropriate in her situation.

Realizing that property is encumbered that there is nothing left for other creditors, bankruptcy trustee abandoned the house and surrenders to state court to settle issues.Seller believes she should still have interest in the house.

If merely vacant and in bad shape, you will have to give written notice to surrender possession, wait six months, and then file your ejectment lawsuit.