I thought I had found the perfect container at walmart to fill and make blocks of ice for camping. It was slightly tapered so the ice would fall out. It was just a simple (but thin) holder. Alas, it burst and now I have frozen water in my freezer. I need to make 1 quart'ish. blocks of ice. The last so much longer then cubes of ice. Literally 3 days or more in a decent igloo compared to half that for cubes. I need a tapered but somewhat thick plastic container to fill with water that wont split when it freezes. Any suggestions?