I'm so sorry to see this about Wiley. It is such a shocker when you think everything is fine, and then the vet gives you a devastating blow like this. I'm glad that he is doing well right now, and that you have time to totally spoil him and enjoy your last days together.
When I've had dogs on light activity, I've done some find it games in the house. Just hide a little food or a favorite toy, and have him search for it. If even that is too much activity, you can even do the cup game, where you put a piece of food under one of several cups, and have him pick out which one it's in and reward for making the right choice. Not sure if he'd like those games, but thought I'd suggest it, as mine have all loved scent games.
Thinking of you and your special boy.