So my secondary screen died

[-silencer-]

Nice, do you roll that way, on a single 1920x1200 screen?

Nope. I have two 1920x1200 screens on two separate PC's. Main is fullscreen on one, four clones are 960x600 on the other.

For my tastes, any window size smaller than 800x600 isn't usable, so I wouldn't want to cram five clients onto one screen.

This is true. I've got a 22" 1680x1050 monitor showing 4x alts now, but I'm about to go back to another 24" 1920x1200 for the alts. Even after adjusting the UI scaling, the fonts/icons are still too small for how much size the screen has (840x512). 600 is the minimum dimension I'd plan to use for either height or width.