Comment # 4 on bug 1001272 from Nolan Leasy

Alt-drag does work to drag the window up and then I can see the bottom.  I was
not aware of this functionality.

I've seen this issue on 2 different standard laptops, though, and it seems like
the window should be sized as a percentage of the screen size rather than
(apparently) hard-coded pixel dimensions.

This was not an issue in Plasmashell 5.5.x.

My current shell is:

~> plasmashell -v
plasmashell 5.7.95

There seem to be many regression issues in the latest releases of KDE Plasma.