Subscribing to ESPN+ gets you all out-of-market and non-nationally televised games. All in-market and nationally televised games will be blacked out. So you'd also have to get a cable/streaming package that includes the regional sports networks AND the national channels (ABC, ESPN, TNT, and the dreaded NHL Network) to watch everything.
So, for example: I'm a Caps fan who moved to Philly years ago. I use ESPN+ bundled with Hulu Live (which includes ABC, ESPN, TNT, and the regional sports networks), so that I can watch the regular Caps games on ESPN+, the Caps/Flyers games on the RSN, and most of the nationally broadcast Caps games (which will, hopefully, include the playoffs). The only exception is the national games on NHL Network, because they're the worst and not available on Hulu Live or YouTube.TV. You have to either have cable, Direct TV, or Fubo, and I'm pretty sure you have to pay extra for the extended sports tiers of those services just to get NHLN.
I used to use NHL.TV, and it was so, soooo much better than ESPN+. It also included NHL Network games. But it's gone in the US now. At least ESPN+ is relatively cheap. (And, as mentioned, if you're a cord-cutter but want streaming cable, the Hulu Live and Disney and ESPN+ is a decent value.)