What Happens to the IRS during the Shutdown

We're now into the third shutdown of federal offices this year. The other two were brief closures back in January and February.
Will this latest federal government shutdown, which began at midnight today (Saturday, Dec. 22) be similarly short-lived? Maybe, but closure #3 of 2018 already is the longest of the year, with the January shutdown lasting three days and the one in early February technically shutting federal doors for just a few hours.
Nothing is expected to happen until after Christmas. Some are predicting the impasse will continue into the new year. Temporary funding for the IRS was enacted in the Continuing Appropriations Act, 2018, Division D of P.L. 115-56, and extended up to Dec. 22 by P.L. 115-90. Congressional negotiators are currently working on a continuing spending resolution that would fund the federal government through Feb. 8.
In anticipation of a lapse in funding, Treasury in late November issued a fiscal year 2019 “Lapsed Appropriations Contingency Plan” th…
In anticipation of a lapse in funding, Treasury in late November issued a fiscal year 2019 “Lapsed Appropriations Contingency Plan” th…