If three semifinalists can’t play because of COVID, the one that can play will be declared national champion. If one team can’t play, its opponent wins by forfeit. If one semifinal game is cancelled because both teams are out, the winner of the other semifinal is the NC.
The semifinals can’t be delayed; the NCG can by up to four days. But if one team still can’t go on the rescheduled date, forfeit time.
The quarantine period for positive COVID test recommended by CDC is 10 days from either first experiencing symptoms or, if asymptomatic, 10 days from positive test. Depending on when they first had symptoms or tested positive, they’ll most likely be clear of quarantine by NYE.
Anybody testing positive going forward is going to be out for game day.