[quickslowdown]

For anyone else who gets stuck with a window where the draggable part is off-screen on Windows, if you click the icon in the taskbar to "focus" the window, hold Win+Shift and hit the up arrow, it'll maximize the window so you can see the controls. If it's on a different monitor, or on a "ghost" monitor your computer thinks is plugged in but isn't actually, use Win+Shift and left/right arrow keys until you can see the window :)

Still a very stupid problem to have to solve.