Hi and welcome to the boards! You sound like you are doing really well. You can certainly try a dreamfeed, if he is waking for a feed then feeding a little earlier may keep him asleep through to the next feed. When does he wake for a feed after the 2/3am feed? If this is it until 7 ish he is doing really well. Not all babies take to a dreamfeed, it's really hit and miss with my LO, so give it at least a week to see what the effects are.
Let him guide you as to when he needs bigger feeds. When he starts draining 4oz bottles put another oz in for him, there should be enough in the bottle so there is a bit left so you know they have stopped because they have had enough not because it's all gone! There isn't really a set age for increasing bottles, some never take more than 4 or 5 oz whilst others are on full bottles quite soon.
He is very young to sleep through the night yet, my 14 week old has a night feed and although some do sleep 12 ish hours at a young age it's very common to need the night feed for some months.
If you want some more advice about his routine post on the EASY board, but really he is so little make sure you enjoy him! We have a rough EASY, it's not so structured time wise but I try to be guided by her and follow the main principles like not letting her get too overtired and keeping feed and sleep seperated.
HTH!
Laura