I was just looking into this today. It appears that the ESPN+ maybe the only option but there is no info on if they will be showing all the games (not nationally broadcasts) like NHL TV did. $69 for the year for ESPN+ seems cheap with all their content.
Quick google found this.
The out-of-market streaming service NHL.TV will cease to exist, with its functions folded into ESPN+. Starting this fall, all 1,000+ locally broadcast games will be available to ESPN+ subscribers, save local team games (which'll be blacked out). Cable's NHL Center Ice out-of-market service will still exist.Mar 12, 2021