The most important thing you can do is have a discussion before the move about expectations you each have for the amount of time you as a child can spend
with your father. The worst situation that I see is when parents move to be closer to a child and then find that child is not able to give them the time they expected.
Talk to your dad, and discuss how much time you do have to spend with him, and how much time he thinks you should spend with him. Come to a conclusion that works for both of you.
It’s a great idea for him to move close to you if it's what you both want. My mother had nine strokes and she stayed where she was because of my sister, but I would have loved to have had her close.