Quick answer to your question: I'm using about 12 liters.

But a good answer depends greatly on some variables specific to your own circumstances:

• air temperature of your kitchen
• what's inside your fridge (empty space vs. thermal mass)
• the size of your fridge
• how well insulated it is
• how well maintained it is
• how often the door is opened
• how long the door stays open
• whether the door opens out, or up
• whether it has both refrigerator and freezer units
• how cold the ice/water jugs are

I've noticed the fridge consumes more electricity in summer, as we don't have AC, and I keep the house between roughly 54-60F (12C to 15C) in winter. In summer the kitchen ranges from 16C in the morning to up to 33C, although with shading improvements it's now more often 26-27C in summer.

I've also noticed a big difference in the jugs when the overnight low is -26C vs. -6C. At the coldest level, the jugs don't thaw in the fridge for 2 days at least, while a minor freeze gives at most a day of free cooling.

Our fridge is of the style with a refrigerator section above and a freezer drawer below. They are in separate, insulated compartments with their own access doors. I assume that with the ice in the fridge, almost all if not all of the electricity used is to keep the freezer cool.

I'm guessing at the usage based on a couple observations: 1) our LFP battery that we use for the fridge etc. during peak pricing times drains much slower with the ice and 2) the fridge is noticeably quieter with the ice jugs. It would be better to measure for a month with a kill-a-watt tool.