My granddad had it, but he became quite aggressive and ended his life in the elderly ward of a mental hospital, although I have to say, he was very well cared for there and the staff were mindful of his dignity at all times. For an NHS hospital, that's saying something.
He had been a very intelligent, independant and upstanding man, and it was hard to see him going downhill towards the end of his life. Saying that, there was no way we could have cared for him at home, plus we know that's not what he would have wanted. He'd not have wanted to be thought of by his family as in need of care.
As long as your father is coping, then him having your mother at home is probably the best thing for her - familiarity and all that. If things deteriorate, then there is help and support available for all of you. Make the most of whatever you're offered.