“Never wake a sleeping baby at night”??

My 10 week old sleeps well at night. For some reason always has. Since birth we’ve been waking her for feeds every 3/4 hrs in the night. She is formula fed. She gets plenty during the day, is a healthy baby and gaining weight well. Now we are wondering if we can relax with waking her at night? If she were to go 5/6hrs sleeping would this be too much? Is she still too young and if so when will she be old enough? Lots of experienced parents say to us “Don’t wake a sleeping baby at night!” But NHS advice says to continue feeding them at night until 6 months. However it doesn’t distinguish whether this is “continue if they want it” or wake them to offer it!k