My 12 week old is mostly sleeping through the n...

My 12 week old is mostly sleeping through the night now. My dilemma is trying to get all his bottles into him throughout the day?? I would usually feed him 4 hourly, but if he wakes at 0530, I usually have him settled for the night by 1900 and that only allows for 4 bottles. My CHN says to fit in the 5 bottles required, this would give him his required mls/kg for the day. My mum (who has been right on everything so far), says just to give him his 4 bottles and he'll wake if he's hungry. He takes what's given to him whenever...Not sure what to do.