Got home from the airport last night (Sunday) at 11 pm. No food in the house, and starving. Check what's open: Mi Gia Phung. Why not try it?
Ordered the deep fried spring rolls, the large Thai-style pho (me) and the medium vegetarian pho (Jackie). All were delicious.
Apparently they don't necessarily close at midnight, it's whenever they stop getting business, which "might be 11 pm, might be 2 am". So that's kind of annoying because you can't count on them being open if you roll in at 11:15 pm, but if you're lucky they might be open even later.
Most importantly though, the food was delicious and the waitress was friendly (I think her parents might own the place? They were hanging out in the back.) Will definitely return.