Once he wakes up and asks for it, I would feed him immediately, hun, so that you could both get some more sleep. Well, not at first grunt per se, let him wake up and ask for it - sometimes they do wake a bit, make a few noises, roll over and go back to sleep -- so S.L.O.W down (Stop, Listen, Observe, figure out What's up), wait a bit before responding - don't watch the clock or anything, just pause yk and see whether he is truly waking