The entire discussion hinges on a couple things; Whether you think this team has a realistic, genuine shot at the Cup during Geno's next contract, and whether you think Geno is still an elite player when he's healthy. I don't, for either factor. Window's closed, and Geno's as likely (or more so) to look like a dude really struggling as he is to look like a bonafide game-changing 1C/2C on any given night. You also can't ignore the fact that he's pretty much a lock to miss 25ish games a season, and that's not getting better with age, and wear and tear piling up.
As soon as you remove the whole "I've watched him for like 18 years and am too emotionally attached" thing, it's not really a smart idea to keep Geno around at all costs. If he's re-signed--which, for the record, I'd be absolutely astonished if he wasn't--it'll be a decision made by the team driven heavily on ~legacy~ and jersey/ticket sales. Not because he's worth the $8 million+ he's probably going to ask for, and get.