You can't save anyone. You can't make your Dad's grief less, it's his to deal with. If you move, you can still offer support. If your father gets upset, he gets upset. You have no control over that.

It seems that you and your H need to continue talking about what your options are.

Me 57/H 58
M36 S 2.5yrs R 12/13

Let me give up the need to know why things happen as they do.
I will never know and constant wondering is constant suffering.
Caroline Myss