We are flying from Denver to GNP in late August. It is about $1000 cheaper for the 2 of us to fly into Missoula than Kalispell, but we are arriving about 8:30 pm. How long would the drive take from Missoula to GNP at night? Would road construction be a problem then? We have reservations at a B&B near GNP but I guess an alternative would be to spend the 1st night somewhere along the way. Thoughts?