Tickets are doable, although it may depend on the timing of the series. For example, any series that takes place while the students are out usually is: (a) cheaper; and (b) easier to get tickets. Of course, then you also miss the student section's antics (if you care for such things). For what it's worth, you can still get face value tickets for the Cornell series this year right after New Years.
My best advice is to keep an eye out for when single game tickets go on sale, and then try to log into Ticketmaster (sorry, that's who the school uses) at that time and buy tickets. There are also usually a few hundred seats made available through the opposing school, so you could also reach out to QU's athletic department (although, these often go to parents). If that all fails, there is usually a secondary market on Stubhub, Seatgeek, or Ticketmaster...although you'll likely pay 50-100% more than face value.
Tickets this year were reduced (not sure if UND intends that to be permanent or a temporary Covid price reduction) to about $25-30/ticket (before fees) to get in. Usually, it is closer to $40-45/ticket (before fees) for a good non-conference opponent.
In any event, if you really want to make it to Grand Forks for a series, you can get tickets, and to the extent you are striking out in every feasible way, contact me directly. I'll make sure you can get in the building (assuming you don't have a group of like 15-20 or something, and assuming you give me at least a few days). : )