Well, there are lots of ways to look at a life's work and worth. One is to see it in qualitative terms: how much money can one earn; who much of something can one accomplish? Another way is that of (most) excellent teachers: a compelling need to meet the next class each September, believing that one does something (and one never knows what that "thing" is) to help at least some of the students. I believe that Geno's a born teacher--of technical basketball mechanics, discipline, life lessons. It's hard to drag oneself in at first, because it does get a bit "old", but once engaged, I'm sure Geno will see challenges and rewards in everything he does.
So, I don't think there's a number out there (so many NC's that no one will ever catch him; more career wins that Pat Summit). Rather, one year he'll show up in September and feel that his heart's no longer in it. If it stays that way by Feb. or March, he'll announce his impending retirement and give UConn good lead time for his replacement. Alternatively, he'll figure out a way to stay involved until his then current crop of recruits graduate, but of course that could be too complex and take too long.