Um - it depends. To be honest, I usually worked really hard to pump always a bit MORE than I knew Kieran would take. (We gave up the df a couple of weeks ago because he started taking only 1 or 2 oz and then waking at 3 anyway).
Some nights he took 6 oz. And this was at only 3 months old. Some nights it was 3 oz, and then he'd sleep until 5 or 6 anyway.
What I would suggest you do, is perhaps pump twice. Pump immediately after the very last feed of the day, and then pump again just before df time as you have been doing. I got into the habit of pumping a little bit all day - eg if first feed of the day was on the left boob, I'd pump it after he'd finished, maybe get 1/2 oz. Keep doing this all day and you'll soon have a respectable dinner for your LO!
If he's regularly been taking 5 oz at the df, I'd definitely try to up it. See if you can pump 6 and if he will take it all. If so, pump 6 1/2. Within a week you'll have an average worked out (say he always takes 6 1/2) and then you'll make sure that you always have 7 in case he's extra hungry some nights. This way you can keep track of how much he wants - if he regularly starts taking 7 you knwo it's time to up the amount to 7 1/2.
Babies do want more food as they get older, and though I know they don't like as much increase in volume of breast milk as they do of formula, his little stomach is definitely getting bigger.
And yes, he probably will sleep longer, the more you can get him to eat.
