Could you get him Out of MAYO?
In order to avoid EMTALA violations, what would have to happen is the family would have to have an accepting physician at a different institution and there would have to be a hospital to hospital transfer — the family is free to attempt to find a receiving facility — but then the cost of transfer would fall to the family.
You can sign a patient out at any time. They will threaten you with going AMA....but you can still do it. They should take this man to another hospital.