Wow!! I have the vacation days to do this. I called Montana FWP (Fish Wildlife and Parks) to talk about the cost for a license. $110 for non resident. 50 bucks for 3 day non preserve, but you cannot hunt Pheasant the first week of the season with that permit, and you cannot hunt sage grouse at all with it.
Good luck to you and whoever goes with you though... that would be an awesome trip.