To be fair, the rivalry is not as heated as it used to be. Sure, there's a few more penalties, maybe the occasional brawl every few seasons. From what I've heard about the past though, it's not on the level it once was.
I think this may be an instance where Tech and Northern could consider ditching the Superior Showcase and work together to schedule a couple non-conference opponents as a sort of "Yooper Icebreaker". Similar to how UAA and UAF host and play in each other's showcases, but have another weekend to meet and settle the Governor's Cup. It would have to be on a smaller scale though - two opponents and one weekend. Swap opponents between Friday & Saturday, and probably expect to reciprocate the following year. This may be a good way to target some of the ECAC schools that have an easy 'travel partner'/geographic rival.
Nevertheless, it's funny how NMU wins 20 games, goes to the tourney, and all of a sudden the fans think that other schools are beating down the door to schedule a non-conference series at the Berry with them. Northern's notoriously cash strapped athletic department schedules Tech because it's convenient, inexpensive, and historically cute to do so. The series with Tech isn't going anywhere until a few million in travel expenses magically appears in their bank account.
Now, if both these teams happened to be decent for a spell, the rivalry could certainly gather steam again.