"I also think Tennessee and North Carolina are overrepresented by Dems in their delegations, but someone who knows those states would know the specifics of how their seats are drawn up."
Both TN and NC have RAT gerrymanders that, together with the power of incumbency, result in Democrats being overrepresented in Congress. If the GOP could control redistricting in those states, the TN House delegation could go from 5 RATs and 4 Republicans to 7 Republicans and 2 RATs, and the NC House delegation could go from 7 Republicans and 6 Democrats to 10 Republicans and 3 Democrats.
the NC House delegation could go from 7 Republicans and 6 Democrats to 10 Republicans and 3 Democrats. Only with the right candidates, I think. Isolate the Watt, Butterfield, and Chapel Hill districts and split up the rest, and you probably limit the delegation to 3 liberal Dems and 10 moderates/conservatives, mostly Republican.