I go back to work on Monday and will being my at work pumping adventure. Woohoo! Unfortunately I don't have easy access to a fridge. There is a fridge in the teachers' lounge at the other end of the school but honestly it's always packed and kind of gross. Is it okay to store my pumped milk in a cooler with freezer packs? I could buy a used mini fridge if necessary, but I'd prefer not to.