Good luck, I'm going through something similar!
We were feeding between 2:30-3:30, and then she moved it to between 1:30-2:30. Generally either way she sleeps till morning after that, but I'm not sure why she's not stretching till later in the night for her feed. I try hard to keep it at DF plus 1 NF, and all other NW are just resettled (I try to feed only if she wakes up after 1 AM and not before). I rarely have any NW between 3:30-6:15 anymore (occassionally I would get an early WU at 5:30 which I was able to resettle)
4 months is a huge growth spurt and everything changes, so good luck! I'm also watching this post.