I negotiated 38 property "surrenders", I got 100% payment including on back rents.

Why are you following this path and not simply surrendering the title to the mobile home, making it part of the real property, and then selling it as a single-family home for cash with a real mortgage on it? 

You would want to see the total amount paid in (including death premium and fees) and have it charted against surrender cash value.

They can surrender sooner if they want but they are entitled to keep the property for the duration of time they paid the rent for.

Bottom line is that unless the spouse surrendering  ownership has a specific provision written into the warranty deed limiting transferability, there is nothing legally he can do to “mess up” a subject to sale.

A transient occupancy terminates when a transient occupant begins to reside elsewhere, surrenders the key to the dwelling, or leaves the dwelling when directed by a law enforcement officer in receipt of an affidavit under subsection (3), the party entitled to possession, or a court.

For the same property I will list for 1400 (surrendering 1200/year) in exchange for dozens of applicants, and always a handful of highly qualified (700+ credit, 3x income, stable work history etc).

First offer Cash for  Keys and a voluntary surrender of the property (get all roommates to sign).Then DISCUSS (not threaten) that the next set would be eviction for late payment and that would show on the Civil Records of a roommates ( must file against all). 

Either party may terminate the month-to-month Renewal Term at the end of any rental month, provided that written notice of not less than thirty (30) days is given to the other party prior to the last day of the desired final rental month of the tenancy.TENANT'S RESPONSIBILITY AT END OF TERM: Tenant agrees to surrender the Property to Landlord at the end of the Initial Term, or any renewal thereof, in the same condition as when received, ordinary wear and tear excepted.

You can ask them the most common reason dogs are surrendered, at the national level it is due to housing.