Scale window contents appropriately to each display
Solution 1:
This is very much not not not (yes: 3 "nots" bad) ideal, but it's the best I can come up with, as I have the same problem as you.
Just individually zoom each program depending on which monitor it is running on to get a size that's more reasonable.
Ex: in LibreOffice use the zoom buttons in the bottom right.
In the terminal use Ctrl + Shift + + to zoom in, Ctrl + - to zoom out, and Ctrl + ) to reset the zoom.
In Google Chrome use Ctrl + + to zoom in, Ctrl + - to zoom out, and Ctrl + ) to reset the zoom.
You get the idea.
This is NOT a great solution. It DOES require re-adjusting the zoom each time you drag a window from one monitor to another, and it IS a pain-in-the-butt.
Shame on you Ubuntu! :)