I'm writing this from my off grid shack.
I have 15kwh of lifepo, and even if it weren't hooked to 4kw of solar I could still run my fridge, charge my phone, and run the fan in my fireplace for 4-6 days... longer if I dump the fridge.
It's 6U of deep 19" rack space.
So 2 x that isn't an entire shed-sized battery.
Though I'd happily have a shed-sized battery... I suspect that delivering and covering something that size would cost more than the batteries I already have, though.
They make hyper-insulated refrigerators for use on ships with limited electricity that use either vacuum insulated panels or aerogel insulation.
> It's 6U of deep 19" rack space.
If the GP commenter is typing in from the UK .. that's a not uncommon garden tool shed size.
By contrast modern Australian farm sheds have clouds forming within them and host birds that seasonally migrate from one side to the other.