So just how small, inexpensive, and portable can a system be made?

Sorta smaller than a tablet, but runs like a big computer

VR headsets seem to be coming on strong

TV computer sticks and Rasberry Pi stuff getting tiny

Small wireless keyboards, some folding, some roll up, etc.

Assorted mice options, rolling, pad, thumball, etc.

VR setups including ways to make a virtual desktop, with standard “office” suite.

The system would be emphasized on portable, light, preferably USB powered.

Could it be used while flying? Maybe running off the planes USB seat port
Or a USB battery pack if flying Dens style, or in remote areas

It would need to do the light stuff:
Paperwork, Excel, emails
At least light surfing like GOC, maybe delve into the YouTube links as well
Wifi yes, cel card no

And be nice if:
Able to access home security video, maybe ring notifications, etc.
Do light video processing (GoPro vids kinda)
Run Steam or other video gaming