NICU and expressing colostrum

Hey ladies! I was told today we're meeting our little one Tuesday (I'll be 36+6) and that some time in the NICU is still quite possible due to some growth and blood flow issues. I plan to breastfeed again but I'm preparing for the possibility of a feeding tube/feeding issues/milk coming in later due to need for C section this time around etc. I've been expressing colostrum since 34 weeks (with ob approval) and was just wondering if any of you might know roughly how much bubs will be going through each day? I understand every baby is different, just hoping for a rough estimate please:) Thank you very, very much in advance!