The above map of Italy was edited to fit a more vertical viewport. The maps generated using the Google Geochart API have a ~4:3 viewport and some countries do not fit perfectly in this aspect ratio, leaving extra space that could be hidden. When creating a map you can use the ‘Custom CSS Generator’ below the map preview. You’ll the options to change the viewport with some CSS. Below are the values used for this Italy map.
Complete Setup Page Screenshot: