I didn't do this project myself but you can apparently liberate the display out of a laptop. You need a piece called a controller for the particular display and I think an HDMI converter.

Also some models of mobile device can be used as an external monitor. So your phone gives you a bit extra.

There was a subreddit devoted to peoples insane portable computing setups. Like multiple external monitors attached to side of laptop.. In a coffee shop or at the park. Idr the name of it off the top of my head.

And since VR got brought up I'll also ask if you have considered a projector. For the sake of completeness.