Another thought. The nihilism is so ingrained that he may never pull out of it. In a non judgemental, non confrontational way, sit down with him and ask what he wants for his funeral. Where does he want to be buried. Ask him to consider a pre planning meeting at a funeral home near you and put a deposit toward the expenses.

Fourteen years ago when I had my stage 4 diagnosis I planned and prepaid for mine. It felt good to get the dying stuff out of the way.