Worst case, they take possession, sell it for a higher price, and get their money back.

Negotiating skills are something we all possess, but the onus is on negotiating effectively so that neither you nor your buyer looses.

From what your describe, there's no adverse possession situation.

I would focus on having a valid right to take possession of the property.If they really have jobs then consider getting a judgment and garnishing their wages.John Corey

These are people who are still in possession of their property and still have time.

Pawn shops take possession while others hold a document (auto loans) but not the asset.You need a good repo man if you do not hold the asset.John Corey

The auction is the point where someone elses, often the foreclosing lender, takes possession. .

Much like an attorney having possession of client funds, say in a trust account...

Did a sheriff or bailiff declare that the remaining possessions were junk and could be taken to the dump or set on the curb?

The more sigs you have, the more people can share in the responsibility when things go bad.Remember, if they have possession, they are, arguably, a tenant- with or without a written agreement.