I think it’s a very big deal to them but to what degree kind of depends on the venue. Wrigley is not a pleasant place to play. Atlanta is a far better team at home, so it would be very important against them.
I don’t know if it would necessarily be a huge deal against the Dodgers in a 2-3-2 NLCS matchup.
You could throw Miz and Henderson right off the bat and try to steal a game, then get to go to Milwaukee for 3, where you might have to use a guy like Harrison who has struggled but is also much better at home.