This marketing issue has been touched on before, but here's the long and the short of it.
The NHL isn't going to expand much when marketing. International hockey fans aren't going to tune in because of the time difference. In Germany, the puck drops well after midnight for the early east coast games. That is an impossibly high non-economic barrier to entry and the league is not easy to follow. Fans can buy merchandise and watch highlights, but that's not going to bring in a lot of money. And chances are, if you are a German hockey fan, you already follow the NHL to an extent. If you are not a hockey fan, you are going to follow your local club and not one in another continent.
The NHL doesn't have a lot to add when they market the teams. European fans follow the individual players, they could care less about the team. Czech fans famously just followed Jagr wherever he went. Russian fans follow Ovechkin, none of them will still watch the Capitals when he leaves. So marketing individual players at the end of the day does nothing. In 10 years, the investment is lost already. Like the KHL's failed European expansion showed, not enough European hockey fans give two cares about teams a continent away. It's not worth millions of dollars for a few thousand Slovakians to watch games for a 3-4 years.
It's not the English Premier League. They have games available every weekend in many households that like the sport and at convenient times. Like in America it's the mornings when there is nothing else on. They have a lot to add when they market the league, unlike the NHL. Liverpool, Manchester United, and Chelsea all have increased the club followings internationally, and have created fans for life. It's easy to follow the teams, it's convenient for the fans, it's everything the NHL by nature can't be. The NBA when they made their broadcasts available in China had double the population of the United States tuning in for games. Like the EPL, the NBA has had and still has a lot to add. The NHL doesn't have that immense "market share" potential.
They already had the Oilers and Draisaitl play in Cologne against Haie. Not much else you can do. The best way they can market the NHL is by continuing to have the Global Series, continuing to have a diverse league, and strengthen the individual European leagues. If they add hockey fans in Europe, they at least have the potential to become NHL fans. The NHL website is already available in French, Russian, Finnish, Swedish, Czech, Slovenian, German, and Spanish.
There's better ways to invest NHL marketing dollars than trying to get Europeans to watch the NHL.