I'm not going to take the time to see if the numbers are available from FSN or the Big10 Network but just because UND had the most viewers on one channel doesn't mean they have more viewers than Minnesota and Wisconsin. UND had the most viewers on NBCSSN, a channel that aired zero Minnesota games. I agree that the UND/Minnesota game would get more viewers than a Wisconsin vs whomever game. However, I would bet most Minnesota games will have more viewers than Wisconsin games. Minnesota is a hockey school, Wisconsin does very well with attendance usually, but that doesn't always translate into viewers.
The CBSSN agreement is a bad deal for UND. The exclusivity clause is the part that wrecks it for UND the most. The rest of the deal is actually pretty good for UND and the conference.