It's a subscriber only article, but here are some numbers tweeted by Chris Botta:
NHL US top 5 average TV ratings this season:
Metro area teams (in households per game):
Rangers 93,000 (up 27k from last year)
Flyers 56,000 (down 43k from last year)
Isles 31,000 (up 15k from last year, 2nd largest ratings jump in the NHL)
Devils 12,000 (down 9k from last year)
For what it's worth, Columbus has a higher rating (smaller market), but only average 6,000 households per game.
I never would've thought the Isles had almost 3x as many households viewing their games than the Devils. Understandable that the Devils get bumped to MSG+2 so often.