I'm not even sure what the argument is anymore, all I can say with certainty is:

- It's the CPU cores that draw the most power by far under 100% load. As mentioned almost all the TDP is eaten up by the CPU.

- If you artificially load up both the CPU and GPU you will far exceed the TDP and the system will overheat and shutdown on a std heatsink (I tried it).
This doesn't happen in real life gaming (even using all cores) because both the CPU and GPU fight for memory BW, rather than maxing out their execution resources.

- The GPU is on the CPU-NB power plane, and it's the CPU's stock Vcore that's pumped through the roof


I have figures from my own testing on my laptop i'll dig them out