I stopped the 5am breastfeed when my daughter was 18 months old. Yes, the first night she cried until morning. The next two nights, she did actually fall asleep (at, like, 6.30am the first night and 6am the second night). After that, she stopped waking. For a few weeks she was waking earlier than usual in the morning (like half to 1 hour earlier) but that gradually lengthened out until she was back to sleeping her usual full night.