Preferably 1 39" 4K screen like I have at home.

I use two non-Retina screens with my MBP in clamshell mode. I've found that the Touch Bar MBP has issues with "Unlock with Apple Watch" when the laptop is open. I think it's trying to figure out whether to depend on the watch or the fingerprint reader to unlock and it always defaults to fingerprint.

I don't feel like dealing with that OR dealing with two screens of the same image quality and one screen with really high resolution. I'm probably going to upgrade to an ultra-wide at some point.

I am using one ultra wide 21:9. It's basically like having two monitors but without edges. Also it makes media and gaming awesome!

I feel substantially more productive with two screens instead of one, and a little bit more with three instead of two.

I hope, the screens in total, are inclusive of laptop.

1 screen

Ubuntu + workspaces :)