I'm going to give a left-field candidate and say John Yarmuth. Ranking member of the Budget Committee with reliably progressive credentials.
There is a possibility his seat gets ripped apart after the 2020 census.
Kentucky has simple majority veto override, so this is basically assured. The only thing that might save him is a county splitting clause in the state constitution, because his district can fit entirely in Jefferson County (Louisville) and I don't think it is possible to draw a Trump district within that county, even in the least favorable configuration for him. Of course, it's also worth noting that the state supreme court is elected, so who knows how a Republican majority would interpret that clause.