Breastmilk Feeding

I'm EP mum too. Day time I will take her milk out from fridge around 3h after each feed as she has fallen into routine of every 3-4h feeding. Night time i feed formula as she usually wakes up once for milk in middle of night anytime from 3-5am. Once baby routine established will be much easier. Perhaps you can consider taking milk out from fridge and leaving it out at room temperature so that it can be warmed up faster later on when baby starting to wake up. Milk at room temperature (25 deg) can last 4h and once heat up should be consumed with 1h and this goes for unfinished milk too. If after 4h, baby never wake up at least u can put back into fridge. 6h is definitely way too long, and cannot be consumed anymore. Meantime while waiting for milk to heat up, u can try giving pacifier and carry.