GB,
Montana would not make a move to I-AA without running a formal cost benefit analysis to determine the financial feasability of being a WAC program (which would also formally answer the money questions that everyone throws around). Montana would be able to make the move if it can be shown to be feasable from a financial perspective. On the other hand, Montana State's athletic programs are heavily subsidized from state money (to the tune of nearly $1M per year more than Montana). Montana has the resources to join the WAC, Montana State does not. Show the regents that the money is better in the WAC, and they won't stop Montana from going, regardless of what Montana State does.
One other thing is that joining the WAC would give Montana additional scholarships. The athletic department exists to convert fan and alumni dollars into cash for students. If it would better serve that function in the WAC, it should be in the WAC. If it would better serve that function in the 'Sky, it should be in the 'Sky.
What concerns me is that the university is unlikely to do such an analysis as long as King George is in power. Montana has had an obscene amount of revenue diverted away from the athletic department, which would come to light if a formal study were done.