In winter I turn up the max temperature of my water heater. This way I can soak more energy into it when it's "off-peak" (cheaper) hours for electricity. You

In winter I turn up the max temperature of my water heater. This way I can soak more energy into it when it's "off-peak" (cheaper) hours for electricity. You just have to be careful not opening the tap on the hottest temperatures anymore. I don't see how you picture it with the fridge though. Aren't you limited by the fact that you can't go down much below 0°C ? Or perhaps you add some new mass? Where do you actually put this mass when the fridge is already full?