Can you prepare several bottles with frozen breast milk?

I have a 2.5 month old son and he has been breast fed since birth. He doesn't have any problem with bottle feeding as I have introduced them in the last few weeks. Also, during this time, I have been pumping in between his feedings for the last month and storing it in the freezer in breast milk freezer bags. I have approx. 70 bags with 4-6 oz in each bag. My question is can I thaw 6 or so bags to have enough to make some bottles for him so the sitter just has to warm them up?