How many schools does it take to dissolve the ACC? Because that's how you get out of the GOR, yes?
If it is true that ND is the next focus of the B1G, ND saves a boatload of money if they join after the ACC dissolves. So I would think that ND is going to lobby the B1G to take 4 ACC schools (probably UVA, UNC, Duke, and GT, long time targets of Jim Delaney. Perhaps a Miami or maybe Syracuse to get into the 3rd or 4th most populous states, but not sure how much state markets matter compared to several years ago and the BTN/cable channel model.) Those 5 likely lobby their brothers of VT, NC St, along with Clemson and FSU to approach the SEC (if for some reason they haven't put out feelers already.) SEC will respond if the B1G raids the southeast, because this is the end game and the door to separating from the G5 and demoted P5's.
That's 9 votes out of 15. Majority dissolves? A lot harder to make the numbers work if higher are required, even with the further TV dollar boost if they reform into a P2 (or P3) and break away from the NCAA into a semi-pro league.
ND's Jack Swarbrick said a couple of months ago that he foresaw further schools moving soon (wouldn't name them) and ultimately a few power conferences breaking away from the NCAA. He said the later would probably be in the 2030's, but that date could also have been some political butt covering since that's when the ACC GOR ends. Just like OU and us are always saying we intend to remain in the B12 until our GOR runs out. We'll see.
Anyway, if the ACC dissolves and the SEC reaches 20 and the B1G 21, I'd expect Wash, Oregon, and Stanford to complete them at 24. NorCal is the nation's 5th largest urban agglomeration (after NYC, LA, DC/Balt, and Chicago-passed in the last year by DC/Balt), but you don't need 2 schools to serve it. Hard to see the SEC going to 24 unless ESPN makes it worth it. You could argue there's value in expanding the footprint nationwide, so maybe 4 of ASU, Cal, Utah, Colo, or even Syracuse (don't think a 3rd team in Florida adds much to ESPN as compared to new states.) But my guess is that the SEC stops at 20. OCD folks may not like it, but a B1G-SEC league doesn't have to have equal numbers like an AFC-NFC does.
And it probably wouldn't matter because I expect Congressional pressure will prevent a breakaway from leaving behind a P5 leftovers super conference that lobbies to be included in the breakaway. The Poor But Proud conference probably makes it in, but with separate and inferior TV contracts. Gives the B1G and SEC non-conf cannon fodder (in theory) if the breakaway has such major governing changes that playing G5 is no longer a real option. Best for a complete separation from the G5.
3 P5's of 70-ish schools could have an interesting playoff setup. B1G conf championship in the Rose, SEC in the Sugar, and Poor But Proud in the Orange, all on New Years. Winners get byes while the losers play the winners of 3 wildcard qualifying bowls on campuses, and 4 more wildcard q bowl winners square off. Gives you 10 bowls that matter for the holiday season. Every playoff team ends up playing during the conf champ/bowls round, then you have a 13-team playoff (but really 20.) Lots of games, but lots of money making.
Or if just the B1G and SEC manage to pull away, you get a similar 2 conf champs bowls and 6 wildcard qualifying bowls and a 10-team playoff (but really 16.) Or simplify to just the 2 conf champ bowls, 4 wildcard qualifying bowls and a 6-team playoff (but really 12.) Or a million other ways to do it.
I'm getting way ahead of things, the ACC still may survive without defections into the 2030's. But I wouldn't bet on that.