Maybe I am missing the joke, and I don't know what you mean by "hand waiving," but revenues for 2019 included media rights ($44M, all numbers rounded for simplicity and taken from the EADA report on the University website); tickets ($20M); donations ($18M); conference distributions including bowls ($9.5M) and NCAA distributions ($5.5M); licensing ($9.5M) and parking/concessions/ programs, etc ($3.5M). That's approximately $110M in revenues that is going to be reduced to what, maybe a few million dollars in media rights, donations and some portion of the licensing revenue?
Expenses, on the other hand, include coaching salaries ($22M); support staff ($21M); scholarships ($14M); overhead and facility maintenance ($17.5M); and debt service ($12M). That's roughly $86.5M in expenses that aren't going away, save possible voluntary salary reductions and some staff cuts. They will not have to pay for travel ($8M); guarantees to opponents ($3M); and will save on game day expenses ($4.5M), but the vast majority of their expenses are, as you say, sunk costs.
Will there be creative budgeting and accounting to try to ease the pain? I am sure. Will there be an effort to ramp up donations to try to save sports, fund scholarships and stave off disaster? Yes, but there is no "hand waiving" that will fill the hole in that budget.