I have to chime in. The room with no climate control during a cold winter could get very dry or massively humid, knowing the far NE. You never know what you get there. You'll may find soundboard separations or bridge separations/cracks, etc. Lots of buzzings. The action will also have lots of issues, and then again, when it is reintroduced into a normal climate will come up with new issues, especially if warmed up too quickly.
In other words, you're in for a world of hurt with this piano. Also how old is this Young Chang? If early 90's Chinese made, the grave may have already been dug!
Is there anyway to get any kind of stable warmth or stable 50% humidity around it (Dampp Chaser system) it? This sounds like a nightmare.
At Banff in the winter they left the uprights in the practice huts without heat all winter. Come summer, they seemed to be all right. Of course it's very dry up there.