Both NLDS series currently have one team up two games to none. Historically, what happens then? Well . ..
Checking at b-ref, I found 47 times in the past a team went up 2 games to 0 in a Best-of-Five. From then on:
The team up went 30-17 in game three.
They went 7-10 in game four.
They went 3-7 in game five.
The seven comebacks were: 1981 Dodgers over Astros, 1982 Brewers over the Angels, 1984 Pads over Cubs, 1995 Mariners over the Yanks, 1999 Red Sox over Cleveland, 2000 Yanks over A’s, and 2003 Red Sox over A’s.