There are get functions that return the size of your current display so you can use Move/Resize to resize the window without first doing a resize to fit.
Is there a get function that returns the optimal size of a window? I don't know how to calculate the dimensions that the resize to fit will give me without actually calling resize to fit.
Get ( ScreenWidth ) returns the pixel width of your monitor
Get ( ScreenHeight ) returns the pixel height of your monitor
You can use both expressions in a new window or move/resize window step to compute the needed window dimensions so that they fit within the size of your current monitor.
I don't see an answer to the OP question:
Can (or how does) one find the "Resize to Fit" dimensions so that Move/Resize can be used instead of AdjustWindow?
Get (WindowContentWidth) does NOT do this if the window has been resized to something other than the ResizeToFit dimensions.
And a somewhat related question: Has anyone observed odd repositioning of windows when calling AdjustWindow[ResizeToFit] while the window is displayed on a monitor that is not the first/primary monitor?