City Center - late or early
Bar Room at the Modern is a great idea. They get you in and out fairly quickly and they know that a lot of people eat there before going to City Center. IIRC our host confirmed our curtain time when we were being seated as we did a pre-theatre meal there.
I'd make a reservation, and note that it's pre-theatre. That way they know ahead of time and you don't end up at the lounge tables or banquette, where it's a little less comfortable to eat.
The bar at Ma Peche might be tough. There aren't a lot of tables in the bar area and sometimes the bar area is pretty crowded.