I tried to play the night game and failed miserably. It sounds like a good idea, but when you can't even tell what the terrain looks like, it is really difficult. If I have a night mission, I usually try to use flares sparingly but turn personal lights off, so it is kind of a hybrid. I still bring light, but it's not centered on the gals, so they are not as easy to spot.
Guys in personal armor have good night vision (16) compared to your gals (12), so you will be loosing the pitch black game, especially since the AI knows the terrain whereas, as you said, the player can't see anything.
If you have personal lights on, you are visible form the normal sight range (20) since you are not hiding in the dark. So I guess you still "win" 4 tiles by turning those off. If you can set some light ~20 tiles away for the enemies to step on so you see them (in light, gals have a vision range of 20), while making sure it is pitch black on the Bonny's roof (you will only be seen at 16 tiles), you will spot them first and be able to react/take potshots.
Enemies "remember" you for a number of turns after having seen you, which means that they know exactly the position of a gal for a certain number of turns after spotting her (spotting by the AI is the same as for a gal to stop with the little number appearing on the bottom right, it means they actually saw you). Although they know your position, enemies will not shoot without spotting you again, but they will know the best way (shortest distance) to come spot you. I am not sure if they can throw explosives without spotting you again.
Shooting an enemy or throwing something at them does not reveal you, and I don't think they even "think" to make the connection between where the shot came from and where they need to check. They need to visually see you.