I can attest that my kid’s boarding school will send out an email announcement of the situation and nothing more for boarding parents, since this has happened more than once so far this year.
In fact, my child has had to go to a hotel off campus to attend classes remotely after one outage.
Mysteriously, we did get a robo call one evening earlier this month that they’d let us know by email by 5:45 am if the next day was going to be virtual. I guess some day parents must have complained.