I frequent this branch of le pain most often.
Usually after ordering my dry cappuccino the need to tinkle will follow. They only have one unisex restroom in this branch, but unlike other ones it is conveniently located near the entrance so you don’t have a long awkward walk to the back.
This restroom is also a bit odd in the fact that it has another door inside that is always bolted and loud sounds emanate from. Be prepared to constantly be weary of someone barging in while you pop a squat.
…& while it may be for customers only – they seem pretty lax and it could be possible to just walk right in without much fuss.