We have yet to really see how the math might play out on a 2020 Form 2210.  Gut answer, you're probably okay, but does 30 days really make much of a difference?

Estimate coupons are really just a convenient way for the IRS to know how to apply a payment.  The penalty should inevitably be based on actual payment dates.  So any overpayment from 2019 should be deemed to have been paid on 1/1/20.  Back before the federal government started messing with the space-time continuum, all that mattered was "paid by 4/15/xx."  Now, whether that's "paid by 6/15" or "paid by 7/15", who knows.

My own personal opinion is that 2Q ES payments made by 7/15 will be fine once the dust settles.  A technical reading of the disaster area emergency powers suggests that the IRS is simply granting a grace period for payment so I think any payment made by 7/15 will be deemed to have been made on 4/15.  In the grand scheme of things though, I also don't think 30 days is going to make a difference.  Folks that have the money should just pay it by 6/15 and not risk the uncertainty of how the math ends up working on the 2210.  Folks that don't have the money on 6/15 are not likely to have it by 7/15 either.  IRS interest is cheap compared to credit card interest, so if you don't have it, don't pay it.  Food, health and shelter come first before making a deposit into the IRS non-interest bearing savings account.

I also would not be surprised to see a 2210 waiver similar to what we had in 2018 whereby as long as you paid in 85% of your tax by 1/15/21, no penalty.  I wouldn't bet the farm on it, but that's what I'm seeing in the crystal ball.  Come back in 9 months and see how completely off-base I am. 🙂  Wait, what am I saying?  The IRS still has forms in draft for 2018, better make that 19 months.

Rick