I have a 16" M1 Max that I only got because it was $1500 cheaper than MSRP, and it sucks on planes. I have really long arms and I can barely get it out of my bag without elbowing my neighbor.

A few years ago I saw some very interesting custom ergonomic setups optimized for traveling + flying.

One person with a thinkpad is able to get the monitor to be 180 degrees flat w/ the keyboard, and can hang it off the seat. He also brings a split ergo keyboard with a lap mount.

Another person did something similar with a M1 laptop, but needs an Ipad to act as the external monitor (laptop stays in bag) with a built and designed from scratch split ergo keyboard.