As a way of making somone wake the hell up and pay serious attention, this is a masterpiece.
That might not cause the problems for Montana that it would for some other states. Montana has a lot of open country with few paved roads and other infastructure that would depend on federal money. The school system will have to cut back- but in the long run going back to the basic education without oversight of the feds might well improve the schools. Montana could increase it’s state tax in order to collect the money it’s residents would ordinarily pay to the feds, and use that money to make up for the lack of federal funding.
I think Montana would do just fine on it’s own.