a failed system exposed to 7 hours of -40 versus 1 hour of -40 temps would be a difference. I am not rated on boeing so I ask: does the failure of a HYD C sys result in a "Land ASAP" situation or Emergency status.
It does not, I don't think the "what if" question entered their minds as to the alternate system failing, it is an electric release that lets the gear fall on its own weight, I don't see them thinking about temperature exposure any more that you would think about it when you operate the gear normally, it is the same up lock system that you are commanding to release when you operate the gear normally anyway