They will also have a lot lower costs. If school isn't in session, there's not tuition, room, board, scholarship cost. If football doesn't go, no other team goes either, so all of those AD costs will be meaningfully lower as well.
There will definitely be shortfalls, I don't want to minimize that. But if revenues drop by $78 million *and* costs drop by $50 million, you don't have a $78 million hole, you have a $28 million one. It still sucks, but it's at least a little bit easier to manage.
A lot of high paid football coaches are probably going to be learning all about "force majeure" really soon too (the smart ones are already reading about it, and will announce the are "foregoing" x% of their salary until the teams are back practicing and/or they can be back on the road recruiting - what I would seriously think about doing if I were in their shoes is to ask the AD to push the whole contract back by a year: if I'm in year 2 of a five year contract, we essentially insert one year that starts now in which I'm paid a reasonable minimum salary, then a year from now, I pick back up right where I'm at now in the contract structure).