2020 US Presidential Election and 2020 MT US Senate Election-Could Democrats perform well in MT if

Tester-(assuming he wins re-election in 2018) is the 2020 Democratic Vice Presidential runningmate to either Cory Booker or Kamala Harris and Bullock runs for the US Senate in 2020 against Daines-R?
If Tester is elected Vice President in November 2020, he needs to resign from the US Senate in December 2020 so Bullock can appoint Tester's US Senate successor-Schweitzer,Quist,Lindeen,Juneau,or Curtis to the US Senate. MT could have 2 Democratic US Senators since 2014.