Windows 10: Multiple monitors - portrait - side by side

When I set my two monitors into portrait mode and place them "side-by-side" which actually is "top-to-bottom", the desktop background picture looks fine, distributed across both monitors. But when I fire up something like Youtube, my browser only shows on one monitor, and when I play a video, go full-screen, it only plays on the one monitor.

Is there a way to make the 2 monitors act as 1 big one ?

Windows 10 Pro

:)

 

HDMI Multiple Monitors Vexation

I am developing a multiple monitor system. My computer has a single HDMI port so I will need to purchase a splitter of some sorts. I have become lost in all the jargon, technical specifications, and the wide range of prices.


Here is my rough outline: one to three additional monitors with each having the capability of independent rotation between Portrait and Landscape; independent zoom; maximum resolution for fine print text; and last but not least, I wish to place independent content on each, not just replicate the content on one multiple times.

Thanks for any suggestions and recommendations.

 

Change Monitor to Portrait

Portrait monitor not landscapped

 

snap window with multiple monitors in portrait display mode

How can we use snap features in Windows 10 if our multiple monitors are in portrait display mode? One idea was:

"You can assign new hotkeys (like Ctrl + Alt + Up/Down) on the Settings > Functions tab. The functions you're looking for are called "Size and Move Window to Top/Bottom Side"

I cannot find "Settings > Functions" or a "hotkeys editor" to do this.