I'm a little hesitant to define the top end Dman with a point total. I can think of a dman right away who I wouldn't label as a championship quality #1 dman despite his point totals.
It's someone who can effectively play alot of minutes against the best players in the world and do the job better than most. Someone who can make clean breakouts like clockwork under stress. Someone who can play all situations, and carry a higher load when injuries inevitably take place.
When you have that guy, and the domino effect it takes on the existing dman who slide to the next chair, it would be such a massive game changer.
Of course, it's easier said than done, but that's the difference between just getting better, and becoming an elite year in year out contender for the top prize.