Breastfeeding working moms

I start work on Sunday 😭😭😭 I’m so bummed and super nervous to leave my 8 week old with anyone but me, mostly because she was breastfed 90% of the time. When she’d be alone for a few hours with her grandparents, I’d leave freshly pumped milk in the fridge as a “just in case” for them. But now I have no idea how much my daughter drinks in a day. I do 5 eight hour days and each one of my stored breastmilk has between 4-6 oz. so for moms that went back to work already, how many bags of breastmilk did you thaw for the amount of time you were gone?