This is on the breastfeeding board too but I haven't had a whole lot of succcess getting responses over there...
How much expressed BM would an 8-week old need to get through 2.5 days away from mom (estimated)?
Next
month DH and I will be going out-of-town from Friday afternoon until
Sunday afternoon, without DD - she will be staying with grandma. I had
planned to have her on formula while she's at DC starting March 31
(because I didn't have much of a stash due to taming an oversupply) and
nursing at home but am now planning to have half-and-half bottles until I
can build enough of a stash to send all BM, because I am starting to
pump more frequently. I had planned on having her on all formula that
weekend (with a BM feeding AM and PM) but am now thinking I'd like her
to get more BM or half-and-half.
Re: XP: How much expressed milk?
I would say play it safe with around 40 oz. That is four ounces (a lot) per feeding about every three hours.
If you do half and half, maybe only do 20 oz? How much is she eating right now?
I don't really know how much (although I do know how often) she is eating right now, since she's pretty much EBF except when she stays with her grandparents while we're out once in a while. She has taken a 4-ounce bottle before though, that I know, but I think it was too much for her because she was incredibly sleepy afterward.
20 oz wouldn't be so hard to get, maybe I'll send 20-30 (if I have it) and ask her to do as many half-and-half as she can with full-BM feedings AM and PM (since I'll always be nursing AM and PM). Then not stress if she gets more formula than usual... if it makes her gassy, Grandma will have to deal with it.
https://www.kellymom.com/bf/pumping/milkcalc.html
This website is full of info on breastfeeding. Highly recommend.