Re: Vacation without baby who will be almost 7 months
It depends on the baby. There's a range of intake- kellymom says it's 19-30 oz per day, on average (see http://kellymom.com/bf/pumpingmoms/pumping/milkcalc/). Since most babies don't begin to take significant quantities of solid foods until they are much closer to a year, or even over a year, I think you should aim to leave 30 or so oz per day of absence. That way there's a bit extra, just in case the grandparents are burning through the milk faster than you think, or in case a bottle spills all over the place. At just 7 months, solids should not be used to complement but not replace breastmilk in the baby's diet.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"