For posterity, a few charts on cost per month of a few ideas:

First, here's the cumulative share of the labor force sorted by occupational contact intensity (proxy for Covid risk). Would cost $108bn per month to pay wages of those in high contact occupations.

Here's cumulative cost of payroll support per month by business size ($251bn per month for biz with fewer than 500 employees)

And here's cost of 100% revenue replacement per month by business size. Extraordinarily expensive relative to payroll cost replacement as payroll typically is about 20% of total cost.

Had to make a few assumption here (ie margins unchanged since 2017 so they're scaled accordingly with national compensation costs up to 2019Q4).

Also, source of occupational data: https://www.stlouisfed.org/on-the-economy/2020/march/social-distancing-contact-intensive-occupations