living without a fridge/freezer

[Grumpy Grandpa]

I have just been talking to the other half about this, and she suggested that because a fridge or freezer is insulated that the fridge wouldn't keep cool enough if placed in the ground as I have suggested.
So, with that in mind, maybe a single skinned metal box may work much better

....any thoughts?

I think you might be right HL (apologies to your Missus! ). Just as the inside of a freezer will gradually warm up with the power off, so, I would think, will it gradually get cold enough when buried, the insulation then protecting the lowered temperature from fluctuations. How long that might take, I've no idea...