Single party congressional delegations (that is, both House and Senate):
Republicans turned ID, KS all Republican. Democrats gained DE, HA. Democrats retain a 5-3 edge in single party delegations (counting Lieberman and Sanders as Dems), with CT, MA, RI, VT, DE, HA versus ID, KS, WY for GOP.
It seems unusual as smaller states are most likely to have one party Congressional delegations and smaller states tend to be Republican. However, this is mostly a function of Democratic Senators from small Republican-leaning states who might not have survived had they been up for re-election this year.
If we go House only, it's tied at 7-7 (GOP adding MT, ND, SD, NE and Democrats adding ME and MA).