I'm not sure about that. The shorter transistors would allow for tighter packing of the transistors. This leaves less air in between for heat to dissipate.
I'm not a chip designer though that would be my father. Things are way more complicated in the 100s of atoms than in the 1000s of atoms. Part of the reason the cpu's run more efficient is they don't run it at full speed all the time. They have step down logic for the processor. Depending on load.
Of course I am not an EE so I could be mistaken, but I then blame my Computer Architecture prof.