As it happens though, with the navigation design they chose, the entries wouldn't fit at that width.
They certainly could have added an extra breakpoint where the navigation becomes smaller before bailing to a hamburger, but of course that does add complexity.
I suppose, but "Deliver with Just Eat" is a pretty long, and an overall odd choice for a top menu item. Wasn't clear to me that it meant "drive for us". And that's what's eating the width.