You reminded me of something... back in the late 60's early 70's you could buy a half gallon of milk in a cardboard container. My Mom use to rinse them out, fill them with water, and then freeze them when went camping at Letchworth. Tore off the cardboard and you had a block of ice.
Things are looking better for us , see post #1 for reference... hopefully Nobody takes a major hit, newest update at 11pm or so.