The sectors I fly vary in length from 2 hours to 13 hours. Day and night. I think I have a reasonable idea from 28 years of doing it, how to define it.
As I stated earlier, there will be differences on aircraft types, but the two I currently operate only permit temperature control from the flight deck. So any request for variations must come from the cabin crew.
In my experience, if the cabin is either too warm or too cold, it is unlikely to result in the crew achieving much rest (wherever they may be sat) due to call bells going off or frequent passenger visits to the proximate galleys.