Alright so I am flying to melbourne and I need to take a frozen bag of EBM with me... My question is do virgin let you take it on the flight??

And also the reason we are taking it is because there is a 2-3 hour drive from the airport where we are going to, so I was thinking of giving it to bub in the car as I do not want to resort to formula for this so if I have it frozen in its bag it will be thawing from the time we leave home till we get in approx 4 or so hours is this going to be ok thawing on its own in a little esky bag with ice packs??