you could always buy a larger and smaller one put one inside the other and then fill the gap with a can of expanding foam when you get there to save the space of the polystyrene, just don't get it on your hands or they will be black all weekend!
Alternatively just buy a polystyrene food box like this
https://www.jbpackaging.co.uk/polystyrene-boxes.html
The other option is just buy a cool box when you do the beer run in France and dump it when you leave
Alternatively just buy a polystyrene food box like this
https://www.jbpackaging.co.uk/polystyrene-boxes.html
The other option is just buy a cool box when you do the beer run in France and dump it when you leave