Overnight feeds

I have a 7 week old who was 6lbs 2oz at birth. He regained his birth weight within one week and puts on approx. 0.5lbs a week.

I wake him every 4 hours during the night - which equates to:

Feed at 11pm and go to bed

Wake at 3am and feed

Wake at 7am and feed, and stay up for the day

My Q is - when can I drop the 3am? When can I drop the alarm and let my baby wake me? I am unsure if he would wake on his own as he is very placid and I usually wake up the baby rather than he waking me before the alarm