This guy ice cubes...
https://www.alcademics.com/2015/01/c...-a-cooler.html
Besides cutting holes at the bottom of the tray, this is where I was basically headed with it. And from their research, I'm not sure insulating the bottom half would really help... I'd basically have to insulate the top half and let it freeze, so the air escapes the holes on top (or otherwise turn it over in a pool of water).
