If he doesn't do anything when he barks, then tough love may be best (ignoring him, if possible).
If he has to go to the bathroom, I'd set an alarm for before he wakes up, then go down proactively and let him out to go. Over time, extend the time that you get up (ex. if you get up to let him out at 4:45, after a couple of weeks wake up at 5:00 to let him out).
It's not ideal (been there!) but when you gotta go, you gotta go and you may just have to train him and his body to fit to your schedule.