I'll start with my "best answer" to this one - my third child.
DC3 was doing two 6h stints of sleep, waking for only 5 mins for a single feed in 12h from the day he was born.
I introduced a dream feed and DC3 was then doing 10pm-7am from 3 weeks old.
I then dropped the dreamfeed at 6 weeks old and had a week or so of needing to resettle without feeding in the night.
Then DC3 was sleeping 12h without waking or feeding from 7 weeks old.
I have four children though, the other three were not so easy. But great sleeping, from newborn, does exist (I often read people thinking folks are lying when they say baby was sleeping through early).
DC1: Sleeping 10pm-7am from 13 months. Sleeping 7pm-7am from about 2.5y
DC2: Sleeping in two 6h blocks from 4 months old (he never took to a dreamfeed). Sleeping 7am-7pm from 6 months. He was exclusively breastfed through this.
DC4: Going 10pm-7am without feeding (but was waking) from 7 weeks. Going from 8pm-7am without feeding (but was waking) from 12 weeks old. Sleeping from 8pm-7am without waking inconsistently from about 9 months and consistently from 11 months.