Yeah, the svg file determinates the size of the widget. You could just resize some of the svgs which were previously posted into this thread, although the highlighted button presses look a bit on the funky side there.

When you're done with the resizing, just copy the resized svg into /MyDocs and reload the widget.

I reckon widget width between 760-790 pixels should do the trick, since you should leave some room to each side of the desktop.