If Republicans lose the Senate/House/White House, flipping MT-GOV would likely be the only major consolation prize for the party. I’m not even old enough to really remember the Martz years because it’s been such a long time since the state last had a R governor (especially one as conservative as Gianforte), so going from Bullock and his veto pen to a Republican trifecta under Gianforte would be quite a political sea change. Only DE, WA, and OR have had Republican governors less recently than MT; it’s easily the most important statewide/non-federal election in MT in a long time.
Also AL-Sen unless it's a really massive landslide.