As long as there is no odor, no spoilage, you can drink. It's not that the expiration date is necessarily undrinkable. The last time we had milk in our house like you said, I threw them all away, and what happened? My neighbor's mother-in-law took it back to the house. She said it would be a waste to throw it away, and that it would be fine for her to drink it. I even got a lecture from her.