No freezer. No way that 4 gallons of milk is going to fit. Even 2 would be a stretch. They're dormitory-size fridges. I wouldn't try to store more than a gallon in one.
I've never seen a container of milk bigger than 1 gallon. The title of the thread indicates you will be ordering from Garden Grocer. I don't think Garden Grocer sells a container of milk bigger than 1 gallon.
we fit one gallon with the shelf out. usually have connecting rooms with my daughter so we are able to put stuff in the other frig. My grand daughters love milk.