Hiho.
There are different methods to get the window into your view but as long you see a corner you should be fine resizing the window. Tested it out and even when it's completely off-screen you can get it back on screen where you want it to resize. Right click on the game's task-bar-window and click the option that indicated the window to be moved. Press any arrow key and your mouse should attach (when window is visible) instantly to the game's window so you can freely move it around.
That should solve the problem relatively easy. Later, after the game jam, I make sure the game works on all screen sizes ^^ I am truly sorry about this inconvinience. If this doesn't solve the issue you're having provide me with a screenshot of the issue and I will try to find a solution that will work.
Stay crunchy.
Here's the resized window:
