Hi! Newbie to the whole permie thing here.
What an interesting idea...
Just got 100+ bales of old hay to start building HKs. My plan is to stack the old wood in the center and stack bales 3 high to sort of pen in the leaves etc.
My concern with the cold storage in the bed would be the heat that is generated from the composting. However, it might not be enough to keep it from being plenty cool. We are always trying to make anything we do serve more than one purpose, so I love the idea.
Let us know how it goes!