D.C.
If he will take the formula room temp, then it's easy. Just keep the water already in the bottle in the room, and the powder already measured out. All your husband has to do it dump it in, shake, and feed. Super quick and not to much waiting.
If he needs it warm to take it - then is he on a schedule at all? If you know he's going to wake between 3 and 3:30 to eat, then your husband should set an alarm and get up to warm the bottle at 2:45. Again, I would put the pre-measured water in the bottle in the bottle warmer in your bedroom so at 2:45 all he has to do it hit the on button. When it's warm, dump in the pre-measured formula powder and go in the nursery and do the "dream feed" without the baby waking much. He doesn't need to wait for the baby to wake up and cry, just do it at the right approximate time.