In my opinion this is a race to 20 for the power 5 leagues with the Big 10 and SEC already at 14+2 on the way.
SEC- If they can get ND to say yes (highly unlikely) then adding Clemson, FSU, and Miami would be the best case scenario. When the Big 10 finally takes ND then adding those 3 and a back fill of the biggest remaining brand would still be a net positive.
Big 10- Once ND joins they'll have 17 committed and could either add the two Virginias and BC/Syracuse/Pitt or take Stanford and Cal and a wild card.
ACC- If they have enough members after getting poached by the Big 10 and SEC they could look to add WVU and make a run at the Kansas schools when the Big 12 adds half the Pac. The ACC will have to fight to stay alive but they're are enough decent G5 names they can add to stay in the 15ish member range
Big 12- If they add those Pac schools I would count WVU as the biggest flight risk to the ACC so lets say they are sitting on 17 schools. Adding SMU, Memphis, and a team like Boise would get them to 20 assuming the Kansas schools stay put.
PAC 12/MWC- After the Big 10/12 run through the PAC it looks like there are 4 schools remaining without a home, Stanford, Cal, Oregon State, and Washington State. If the PAC 12 wants to stay alive then they will have to merge with the MWC and finally get to use the Pac 16 name.