The only thing that prevents the ACC from blowing up eventually is ND joining it full time.
If the ACC blows up, where is ND going to go?
Construct a new conference with no draw except itself?
Stay independent with a major inability to schedule anyone of consequence and high likelihood of being on the outside of any playoff system?
It will be a few years, but when/if the ACC self-destructs, ND needs to find a dancing partner.