Help! Not sure what to do with all of these!

Rissa💖 • Military Wife, 12yr old princess! 👑 and a 2yr old & 8 week old boy🌈💙

So I have 3 bags from yesterday and 3 from today. I’d like to combine them into 2 different bags. Obviously my little one can’t eat so many OZ as hes only 7 days old. Can I just take a little from the bag each time I give him at bottle at night or will that break down the milk? Thank you!!