I think he'll do the Jacques Lemaire thing, where he'll be a sort of coach in the sky that gives feedback and has the ear of the GM. Can take more days off and won't have to stress over every little thing.
RDS had an interview with Alain Vigneault the summer he was fired from Vancouver. He showed a little bit of his home office and he said that (I believe the interview was in early July) normally, he's already got his training camp all figured out in terms of schemes, line-ups, etc. I'd bet you anything that they spend a good chunk of their time studying film, trying to figure out new innovations, looking at any way they can get the max out of their lineup. I don't think NHL head coaches have a real off-season and honestly, at some point when your body's giving you clear signs that it's time to take a step back, he would be foolish not to listen.