LO threatening to get kicked out of MC so he can live on his own.

My dad has been in MC for about 6-8 months. He was previously in two assisted living facilities, but got kicked out because he was wandering outside and getting lost (I got calls from police to pick him up). Since the last time this happened, he was moved into a brand new MC wing in the same facility. It's a nice place — lots of great light, art, activities — but he's convinced he doesn't have Alzheimers and thinks he's much better than everyone around him. He refuses to talk to them or make friends. And now he wants his own place. Recently, he's been calling his bank and trying to get all of his money withdrawn so he can "buy a car and get his own place." He definitely shouldn't be driving — sometimes he doesn't know whether its day or night, or how to get to his own room — and he's increasingly unable to care for himself: not showering, putting his clothes on backwards and inside out, playing with extension cords to "fix them" and thereby breaking them, unplugging his heart monitor, thinking my mom is still alive or is 5 different versions of her, the whole thing. My sister is financial POA, but even dad's bank told her that she can't prevent him from stopping payment on the facility so he's get kicked out (his latest threat). We are at our wit's end. Dad has always been arrogant and even narcissistic, not caring about his kids unless he wants something from them. But the constant and even abusive calls are wearing us down. Our two brothers have cut off from him entirely, and my sister's ready to do the same. I know we're told not to argue with them, to distract and delay or just agree. But he could be homeless if he keeps this up. I really don't know what to do. If I take him in, he'll wreck my marriage, he's that difficult.