M1 uses 20W in iddle... 40W in full load.
Apples says it is ~7W in iddle and 39W full load CPU only (not CPU and GPU... you can see here:
https://support.apple.com/en-gb/HT201897) but that is bit unclear how Apple does that calc because real iddle power of Mac Book M1 when you do nothing and have just the descktop opened is near 20W... I suspect iddle power for Apple means the display being shutdown... and of course with CPU and GPU at full load the numbers go heavens (can reach 120W or more).
Same for AnandTech where they test the M1 Max with iddle power at 7W that is probably standby and not iddle at all... they usually explain that in someplace in the article.
Plus the 680m is rated 50W... I really have no ideia what are you talking about.
I 100% assumre you you can't use the 680m in a portable form factor and we are talking only about the GPU... adding the GPU and others componentes you will be closer to 80W than <7W lol
Anyway your "examples" and what needs for a portable handhelp have a big gap... of course you will believe there is tech avaiable for that when a 3TFs GPU is a 15W part
I wonder why Valve didn't release a more powerful or smaller device with that magical 680m option available.