Bob, I've been thinking of ways to reduce my
energy use and my refrigerator is an older model, maybe 12 or 13 cu. ft, with the freezer taking a third of that total. It is too large of an appliance for just me. Not sure that I could do the ice box thing like you. May look into a small 4 cu. ft. unit and check on a small freezer of about the same size.
My next idea is the
water heater, adding a new insulation jacket plus pipe warp and having a timer installed. I like the on demand water heaters, but that would be more work than I want to take on here with this house.
The HVAC system is a heat pump about ten or eleven years old, and I think it's very reasonable in cost. I use ceiling fans and just turned the ac on this week, I also like mine set to 79 or 80. Winter setting of 68 or 69 works for me, I can always put on thicker socks!
Peace