I have a portable external screen that I carry in my backpack when I travel and when I work away from home.

https://a.co/d/6P7gfGA

And this stand

Metal Tablet Stand, a Portable... https://www.amazon.com/dp/B0C4KH2GH3

The monitor is both powered and the video comes from one USB cord. My MacBook Pro can run 5-6 hours while powering the monitor. I couldn’t do that if the laptop by itself only last 3 hours.

Every now and then I use my iPad as a third monitor.