I had an issue where a content management system restricted the layout of the page to have three columns. I wanted the results of a search, which were displayed in a div tag, to expand to fill (almost) the entire width of the screen. After just a bit of tweaking with padding and width, I ended with this:
<div id=”results” style=”margin-left: calc(-50vw + 50%);padding-left: 15px; width: 98vw; “></div>
Note that your mileage may vary. This particular code worked with the arrangements of elements in my page, and I have not tested it thoroughly enough to say it would work in all instances.