FSU and Clemson are gone - as soon as they can pack their stuff. Possibly UNC and UVA as well.
Only question is is it to the SEC or B1G.
Those four schools are the heart of the ACC. Miami isn’t much of a football program anymore, so their departures will make the ACC a second-tier conference. FSU joining the SEC would make a lot of sense given the rivalry with Florida.
Conferences are going the way of the Dodo Bird, eventually all of college football will be run by one big organization, separating teams into divisions, which actually will resemble more the old conferences.
Packing their stuff will have to include figuring out how to void the grant of rights agreement. Unless they can void the GOR, it is highly unlikely that they can afford to leave until the 2030s.
In 3 to 5 years it will all be revised again- two super conferences with teams from the SEC/Big Ten/ACC/Big 12 merging.
They ACC will be a fraction of what it is now- mediocre- and SMU still won’t be getting any revenue.