It probably is the solution. Although, I haven’t been able to make it work yet.
Can’t understand what you mean or how would I use the existing html widget. 
So, I decided to create my own widget that would create the two banners and add them on the sides.
I created a widget: https://github.com/teakap/banner-theme-component
It’s loaded, and I added as a widget to the layout setting but still I am not seeing the widget’s html on the page.