Over their last three playoff games, the Chicago Blackhawks have played 180 minutes of regulation time and 97:32 of overtime. Even with that, they have still played less OT than the Boston Bruins this postseason.
By the way, the 26 overtime playoff games to date is tied second all-time for one playoff year (2001). There were 28 in the 1993 postseason.
Below are each of the 16 team's total playing time entering Monday's Finals Game 3 (thanks to Greg Frank for his idea, research and mathematical skills on this):