3 week old baby sleep- question

How many hours at a time does your three week old usually sleep at night? Mine often gives me a 1.5 hour stretch 🥲 We had a family friend yesterday tell us that her babies slept through the night at 1 and 3 days old 🙃 I know this is obviously NOT normal, but it had me wondering how long other three week olds sleep at a time?

Mine is pretty gassy and reflux so has a hard time sleeping on his own for long periods of time.