Another way to change resolution on a Plasma 5 desktop?

[gary]

I'm running a Debian/Trixie AMD64 workstation with Plasma 5 over X. I'm 
connection remotely to it from my Debian/Bookworm AMD64 laptop using 
Remina/VNC over ssh. The connection is unworkable so I want to reduce 
the remote workstation's resolution. However, when I try using the 
Display Configuration Settings tool, the confirmation dialogue doesn't 
show on my laptop until it's timed out and auto-closes - discarding the 
changes.

Is there another way I can tell Plasma 5 to use a different resolution?
Sorry for a newbie-type question, but Internet searches are just 
bringing up how to use the tool, which isn't helpful.