Best wishes to you and your family Brett.
My own dad just passed in August, but he was not doing great before that. He had had many mini-strokes, and was particularly pissed that he had one in his sleep.
He was a retired mechanical engineer at JPL, worked mostly on their solid propellant rocket boosters. Yes, he was a very smart man, and at the end, very frustrated that he didn't have that capacity anymore. I just kept telling him that it's ok and that that was why I was going to help him.
It's going to be an uphill battle for you. Just try to figure out what you can do, that gives him a little joy, and do it.
Often it might be an odd little thing. For me and him, it was me bringing my girlfriends 90lb labradoodle named "Jack" to see my dad, also named "Jack". He loved seeing that dog.
So every weekend I would do that.
The point is that you can only do what you are able to, so don't get upset with the stuff you can't. Hopefully he will make a recovery from the strokes, but if not, just do what you can and try not to sweat what you can't.
Kind Regards,
Target/Chris Behm