That sounds fine to me. I think feeding on cue is the way to go anyway. We had night feeds at that age too. I don't think size has anything much to do with it sometimes. Riley was 8lb 1 at birth, at five months he must have been at least 18 lbs, and often fed every three hours, sometimes did have longer stretches. I think it depends on your lo and also how comfortable you feel about the frequent feedings. It didn't bother me in the least!