The old 20nm runs a bit hotter but the newer 16nm runs below 60°C when fully unlocked and the fan is louder. Power consumption in mobile mode is an issue but not docked. Anyway N should have manufactured the X1 at 12 or 7nm for the OLED model to give us that unlock.
https://www.youtube.com/watch?v=PTrp6Pzl1Ps
https://www.youtube.com/watch?v=Tl9QnzJrf6g