Quoting M walls:" Mixed formula can be stored in the fridge for at least 24 hours (in a container with a lid) you have ... [snip!] ... made. My feeding chart says 23 oz for a 9-12 month old. Do you plan on breast feeding him again once your new supply comes in"
I'm hoping that if I continue to pump and offer the breast that it will come back, but considering I'm only 10 weeks and already having such serious supply issues, I don't think there is much hope. It won't stop me from trying, though. If my supply does come back, of course I will continue to breast-feed him, but after a year I had planned to transition him to a cup, anyways.
If all else fails, after baby is born (he will be 16ish months), I will pump and feed it to him in a cup instead of regular milk/formula. I don't want to re-introduce him to the breast after baby is born because I don't want there to be a huge jealousy issue between LO and the new baby.