Full width header background image – GeneratePress

I have a full width image that I use on the rest of my website (in development so no link, sorry) and I want to keep the same theme going. It works perfectly in GeneratePress to use the image as the background for header if I customize the theme to set header to full width.

The problem I’m running into is when I float logo left and menu right to match the rest of my site, they go to the edge of the screen as well.

What do I need to do to make background full width but have logo and menu go no wider than the content container below header?

Ideally, I’d like to add a container for them either through the GP Hooks plugin or via child theme, but when I look at the header.php file it’s not clear where that container should go.

Any help would be appreciated.