Hi,
When Aidyn was that age (and for many months afterwards) I would dream feed him his last bottle between 10-11pm, just before we went to bed. Most nights he would sleep through until at least 7am!

I guess if they wake up and need to be settled back to sleep its not classed as sleeping through??.... however I remember having to get up for Aidyn and I was still classing it as sleeping through... probably because it never bothered me and he was easy to get back to sleep.
If he was difficult at all, or I had to get up multiple times, then I would Not class it as sleeping through!
I guess we all see things differently though