Okay, a preface: a lot can happen within a Michelle in a day.
Yesterday, we received news that the birth certificate should be done by the end of next week. Good news! I also asked for a new appointment with the embassy to file our I-600, and we got one for February 8th. Doubly good news, because it is as soon as we can be sure we have the documents, and also because it give some indication that we may not be waiting for weeks for our visa exit interview (not a guarantee, but it's the first positive sign I've seen in months that we may not have to be there, twiddling our thumbs, for weeks).
I was able to book a flight this morning for nothing more than the change fee. I'll be leaving on Tuesday, February 2nd. I'll get to see our girls on February 4th, exactly two months after we left.
I'm not sure if we'll be able to do our IOM (medical) appointment before filing the I-600, but it's okay. Since I'm filing on Monday, I'm not feeling a ton of pressure to have it done beforehand.
Seriously, no matter what, I'm getting on that plane.