2 watts total? I doubt it. The display is a major drain. I went down this rabbit hole years ago and on a 2012-vintage X220 with an i7 I could get it down to just under 6W with the display on minimum brightness, the wifi and Bluetooth off, and a host of configuration options including but not limited to what's available through Powertop and TLP.
I'm sure it's better than 5W and change nowadays but the display is by far the biggest draw and I don't think you'll get down to 2W.
Ah yeah, maybe GPU only. Don't the MacBooks with the onboard discrete GPU have an integrated Intel GPU as well? I'd assume those ones physically power off the big daddy card when it's not needed.
They used to. That’s how they worked but it ended up more trouble than it’s worth. I think they stopped trying to switch it on/off during the Intel era (not sure) but there are no discrete GPUs in the M1 era so far.
Yeah a well lit display can be a huge drain, but of course I can control that. I would hope WiFi/BT don’t use much relative to CPU/display, but I can’t claim to know.
I'm sure it's better than 5W and change nowadays but the display is by far the biggest draw and I don't think you'll get down to 2W.