Window too large when moved to second display

Try adding in a Keyboard Shortcut using system preferences. I have mine to execute the Zoom option located under the Window tab at the top of most browsers and applications. I changed the Command + Return + Shift from the default to my new shortcut zoom.

This will resize the window to fit the screen and if a different/smaller screen size is desired, you can easily resize it using the corners from here.

It is actually much easier to resize from this resized/"Zoomed" window because moving your mouse to any of the computer screen's edges will place you directly over the edge of the window allowing you do resize the screen without mis-clicking (example of mis-clicking: causing another window/application to become active or moving the position/orientation of the window altogether).

Just add in the application you want this shortcut to work for under the App Shortcuts option within the "Keyboard" -> "Shortcuts" sections of system preferences.

As long as any part of the top of the window is visible, then the following will work:

Hold down "Shift" while double-clicking then the window's title bar. 
This will resize the window to fit your screen.