Same thing happened with my grandmother. Widowed, staying in her house, increasingly not capable of really keeping it up, all of her kids begging her to move out. For years. Finally they succeeded in doing so, and within three months she was dead. Let him stay there as long as he wants, focus your energies in helping with repairs, cleaning, etc.
Same here. When my grandfather died, my father and his three sibs argued my grandmother into leaving her home. She was devastated and sank into an even greater sorrow. People may not realize how much meaning, how many sweet, consoling memories and even hopes can be contained in what looks to outsiders like a piece of junk. This is true of people at any age.
One reason that many elderly people become so heartbroken and then die after they are moved to a nursing home is that they lose the sights, places, experiences, objects, and people they love, and with the loss of those things goes the loss of hope that life will someday go back to normal, that things can be happy again. Depression causes a suppression of the immune system. They then get infections, are weakened, get more problems, and finally die.