My 2018 copy of the 1040ES for estimated tax payments states.
"You don’t have to make the payment due January 15, 2020, if you file your 2019 tax return by January 31, 2020, and pay the entire balance due with your return."
So, if the window doesn't open until Jan 27, it looks like I'll be making the Jan 15 estimated payment. I'm surprised that window doesn't open until Jan 31.
There is a draft version of the 1040 instructions, but beware that things may change, if, for example, new legislation is passed.
https://www.irs.gov/pub/irs-dft/i1040gi--dft.pdf