I do this in effect. For things that don't rely on high core counts and memory bandwidth, advanced CPU or GPU features, or complex environments, I use a $150 Chromebook.

These new Intels are desktop CPUs. They also have Performance and Efficiency cores. Ideally, they'd prioritize using E-cores, and only as many as needed to complete tasks within an acceptable period. In effect, though, they're not very smart, and you've got to get into overclocking and undervolting to get them into a state that resembles AMD's TDP-limited ECO Mode that provides 80% of the performance at 50% of the power.