For single core, it wouldn't perform as well as you think because performance per watt is not linear. It would push this hypothetical CPU well into the zone of

For single core, it wouldn't perform as well as you think because performance per watt is not linear. It would push this hypothetical CPU well into the zone of diminishing returns. For multi core you can just look at AMD Epyc CPUs which achieve great performance by using many (up to 128) relatively low power cores. An all core load pulls around 400W of power.