My wife’s uncle was in similar shape as Joe is in. The family had to make all his decisions and remind him or where he was and that he had a son and daughter. He would ask the same 5 questions every 10 minutes. So we gave him a sticky note with all the answers and told him to keep it in his hand. About every 10 minutes he would look at the sticky note and would be satisfied.
How long did he last like that?
Sorry for your loss in advance.