Hard to say without playing with it, but maybe just make the Opportunity name larger and not anchored on the right, and the fields after it not anchored on the right. Is there a reason it has to grow.
You can also use 2 different layouts with an OnLayoutEnter script trigger with some Get functions [Get ( WindowDesktopHeight ) or Get ( WindowDesktopWidth ) ] to determine which monitor you are using to go to the appropriate layout.
With a bit of came playing by using the New WIndow script step to open a new window for the user and then disabling some of the controls you could add your own controls for changing window size, but now, since you aren't actually maximizing the window, you can limit the maximum width of the window. That's a bit of a complicated Kludge, but it might be a way to get around this issue. Resize to Fit might also be a script step to use to resize the window without maximizing it.