FOSS or otherwise
Shove-it, an ancient Windows utility by Phord Software that shoves any half-offscreen windows back onto the monitor so that you can get to all the gadgets. Phenomenally useful. First thing I install on any new build.
Sounds like you need to try a tiling window manager. I find floating windows annoying as fuck, and they make you like super slow and unproductive by allowing windows to overlap or go off the screen. A tiler solves all of these problems, there are many fantastic options on GlazeWM, komorebi, FancyWM or the built-in tiling functionality of Seelen-UI on Windows.