Comment by cosmic_cheese

I make a point of keeping my secondary monitor a "normal" DPI 2560x1440 display precisely to avoid this kind of problem. The loss of legibility has little impact on secondary monitor use cases, and I can easily spot-check my UI and UI graphics work by simply dragging the window over.

High quality normal DPI monitors are so cheap these days that even if multi-monitor isn't one's cup of tea there's not really a good reason to not have one (except maybe space restrictions, in which case a cheap ~16" 1080p/1200p portable monitor from Amazon will serve the purpose nicely).