There's no reason for the ACC to merge when they can cherry pick top brands. I don't think conferences can reasonably go beyond 23 schools. ACC can add UConn, Nova, and 2 of St. John's/Georgetown/Creighton without diluting media revenue for the likes of Butler and DePaul. Gets 18 football teams to play 9 conference games. Gets 22 basketball teams where everybody plays a single round robin, 21 game basketball schedule.
Remainder of the Big East could reconstitute as a midwest mid major stealing from the MVC/AAC/A10 (some combo of Creighton*, Saint Louis, Loyola, Dayton, Butler, DePaul, Marquette, Xavier, Drake, Belmont, Murray State, Northern Iowa, Bradley, Wichita St, etc) and an east coast mid major stealing from the A10/CAA/America East (PC, Seton Hall, Georgetown*, VCU, URI, UVM, Davidson, Richmond, St Bonaventure, St Joe's, Charleston)