No, there's a bigger gap between base PS4/X1X (3x) than Switch in portable vs docked mode (2x) ... 

Besides the Switch has already consumed one more transistor shrink compared to base PS4 (28nm vs 20/16nm) so if Nintendo released a new system in 2023 that only gives them 2 more transistor shrinks to work with so Nintendo's new portable system could easily end up with lower performance than even base X1 if we still assume that perf/watt will linearly scale by 2x with each transistor shrink ... 

First we will see Switch Pro/New which will be around 2x more powerfull than standard Switch.

New Nintendo console will come probably in 2023/2024, and will has around 2 teraflops, 8-12 GB RAM, 1080p screen.

There will be possibly three shrinks - but two of them are half-shrinks, so the math still ends up being right, apparently.

We know from a TSMC panel on a ITRS meeting, if I'm not mistaken, and their aim for pitch sizes, that both their 7 nm and 5 nm are going to be half shrinks, though 10 nm was a full shrink indeed from 20 / 16 nm.

That's assuming, of course, Nintendo will release a new console with a brand-new node, and even then, that it will use all the battery juice for raw power instead of extending its life from the Switch's mere three hours.

Even if it waited until 2027 it's not a guarantee the next TSMC node, indeed a full shrink - 3.5 nm, the last one planned before die stacking - would be widely available, given how long the wait for some recent nodes.

So some people are indeed overestimating the power of the theoretical Switch's sucessor given its undocked mode often loses even to the X360 (the main exception being possibly when the X360 was RAM starved) and that's a 12 year old hardware, from a time die shrinks were much easier as well.

Some people are so obsessed with power...and the future. Enjoy the now or you may have to spend all your time reminiscing about the good old days that you never appreciated.

That doesnt sound likely.... your way too optimistic about these things.

from 150/190 Gflops (2017) -> 1840 Gflops (2023) doesnt sound likely.

Graphics effeciency wont improve x12 over the next 5-6years.

Also theres no way your fitting something like a Xbox One X into a small portable handheld.
Xbox One X can use upwards of 180 watts of power.
Switch when in handheld mode, uses like 16-17watts at most when in handheld mode.

You think in 5years time, we will have improve power effeciency by a factor of 12 or so too?

Get real.
Look how long it takes to go to smaller and smaller processing nodes.
How long will we be stuck at 7nm? will 5nm be soon there after? will it be enough to do what you think possible in 5-6 years? no.

1) Yes by 2027 I think Nintendo should be working on a 3rd model too.
Its way to late to release a switch 2, if they want any multiplats at all after 2020.

2) No, by 2027 you still wont be able to a handheld as powerfull as a xbox one x.
Xbox One X, can use 180watts of power..... its just not going to happend, you wont see a portable reach that powerlevel even by then.

Well Switch 2 will be released before then, but regardless a Switch device released in 2027, pulling a number out of my ass, I'd expect around 4TF of power.

I don't think TSMC's 10nm was their full shrink, it largely shared it's BEOL technology with 20/16nm and it showed since it still didn't compare too favorably to Intel's 14nm process ...

TSMC claims that it's their 7nm that will be a full node shrink and I also think their plan is for 5nm to be a full node shrink too if their making a transition to EUV ... (they can afford 5nm to be a full node shrink if they use a next generation lithography technology as their new basis)

10 years is a long time.

Xbox one OG is 120 watts and only roughly twice as powerful as Switch.   Don't see how pointing today'd wattage for Xbox One X will have any relevance in a decade.

OG Xbox One is more than twice as powerfull..... its atleast 3.3 times in terms of compute. However look at stuff like Memory Bandwidth.
Switch = 25gb/s   vs  Xbox One = 68.3gb/s + 102 Gb/s (from Esram).
The Xbox also has a stronger CPU and a HDD.

A more heavy compute switch would be memory bandwidth starved, and adding better memory bandwidth would drive up such a Switch 2.0 power consumption.

Also lets keep it fair:

Xbox One X is the cloested xbox released to the Switch. So if you want to talk power effiency lets use that.
Its 6 Tflops and ~180watts.

Switch is 393 Gflops and ~18watts.

Xbox One X is ~15.3 times the power of the Switch, and uses ~10 times the power.

ergo the Xbox One X is more power effecient than the Switch is, dispite the switch going for low power low memory bandwidth ram, not haveing a HDD ect.

There is no way a future Switch, in the near future (even by 2027) is able to do what the Xbox One X does now.