I just started putting some potted trees in an unheated building and then started second guessing my plan. I have pomegranates in pots that I want to let grow a little more before they have to brave the winter, and I have pawpaws in pots in order to keep them in the shade more easily until they're mature enough to plant out in full sun, and I have hardy kiwis in pots that I just haven't gotten in the ground yet. I was thinking this building which is just slightly below grade would be a good moderately cool place to overwinter them without freeze-thaw concerns. But now I'm wondering if it will be too warm? Do they need to be exposed to more chill hours than they'll get in a building (that will probably spend most of the winter in the 40s)? And it won't matter that it's completely dark, will it? Any thoughts?