What district would be lost in Alabama?
Assume with Republican control you have to have:
1. VRA district in Birmingham, Selma, and Montgomery (AL-7)
2. Mobile-based district (AL-1)
3. Suburban Birmingham district (AL-6)
4. Huntsville-based district (AL-5)
1st district has to expand east into the 2nd district.
5th district has to expand south into the 4th district.
AL-3 and AL-4 have the most senior Republicans who also happen to be too young to retire. If driven by personalities and the same people are in office in 2020, I imagine Martha Roby loses her seat with some bits going to the 1st (rural south) and 7th (Montgomery) and the rest merging with the 3rd.
An alternative is to divide up the 4th with the 5th taking a big chunk, the 6th getting rid of rural counties south of Shelby and going west, and the 3rd taking up the populous east of the district.