Battery technology is antiquated in comparison to processing technology, even considering modern hardware efficiency. I get the very real concerns with three-hour-battery-life, but portable hardware is basically fucked by default for this kind of software, given the smallish form factor. Batteries just suck, plain and simple. We really, really need some advancements in battery engineering and technology.
Overly simplistic maths probably, but wouldn't you need a doubling (halving) of clockspeeds to go between 720-1080p?
Not really. Thumb rule with all of this stuff is that there's just too many factors to simplify. Quality of assets and target framerate being the two big ones. One game may push from 720p to 1080p fairly easily, whereas another will struggle due to the engine/asset quality.
In the same way so many console games have varying framerate targets and native resolutions, so too I would expect this with the Switch, especially comparing docked to portable.
This is my reasoning as well. I'm wondering if the device even has fans that are only active/necessary while in dock mode.
Entirely possible. Or they're just cranked up higher during docked to accommodate the power draw.
It's also worth noting/repeating that it's an existing feature of the Nvidia Shield Tablet called Console Mode. It turns off the screen and renders at higher res(I think?).
We also see that the screen of the Switch is definitely off when docked.
Pretty much. Modern hardware is seriously so fucking easy to overclock. Almost all PC GPUs dating back years are built to fluctuate in clockrates, and most vendors have their models overclock automatically out of the box. CPUs too are easier to overclock today than they've ever been. I can literally change the clockrate of my GPU right now, between games, by moving a slider.
All Nintendo has to ensure is that the system is receiving a stabilised power draw, and cooling is efficient. That's it.