Free Version: Primary Menu wraps on desktop before hamburger appears

I would like to know how to manage the break point at which the primary menu turns to a hamburger. The menu on our site looks fine in desktop mode at full width and in mobile mode the hamburger comes up correctly. However, in desktop mode as the window width decreases, the menu wraps until it eventually turns to the hamburger. I don’t want the wrapping to happen at all. The only customizing I’ve done with the site is what’s available on the free version Customize and using Additional CSS.

The page I need help with: [log in to see the link]