Hello,
First of all sorry about the request for further clarification but we are not expert on Joomla nor we have set up this website personally, but we are in charge of managing it day by day.
Indeed, I would honestly not know where to intervene regarding the html div settings nor, unfortunately, I can retrieve the Global Settings > General Settings you are referring to.
However, to at least try to facilitate your job in providing us with a suggestion, I can mention that we are currently using a shaper_helix3 - Default template and that the module we use for the footer images is Slideshow CK. I cannot retrieve the specific size we would need but what we are aiming at is to have the banner covering the entire footer and not leaving the small space to the right, as shown in the website screenshot.
Now, with my low level of knowledge of Joomla, I think that we would have to intervene on the template, for example from the menu in the screenshot below.
Inline images 1
Is this the correct way? Or should we only intervene on the Slideshow CK module?
Hope we gave you