I stored some compost in a 55 gallon drum painted black.
Helps it thaw sooner. I take 2 or 3 bucket into the GH, let it
warm up & add a few inches at a time as they grow.
Big "done" compost bin is still frozen. Last falls garden compost bin is thawed but
it needs to "cook" a few more months. When I get some fresh green grass clippings
I'll empty it, then mix in the fresh grass as I put it all back in to get it cooking.
Will be "done compost" around August.