Hi Vanessa,
If he is finishing all his bottles, I would put an extra oz in each bottle to give him the opportunity to take more if he wants it.
At this age 1 night waking is still quite common for a lo. However, have you thought about trying to clusterfeed to enable him to tank up a bit more - this may help and also eliminate the 8ish feed.
You could do your first cluster feed just after the cat nap, then have a bath, then feed again after the bath and then do your wind down routine before bed, and aim for him to be asleep by 7:30.
You can still do the dreamfeed at 10, and this will help him tank up even more.
HTH
Paula x