It’s not ideal, as you’re manually targeting the iPad, but …
Default Viewport Code (change as needed for default mobile devices)
JavaScript code (play with as you like for your own purposes)
if( navigator.userAgent.match(/iPad/i) != null ){ viewport = document.querySelector("meta[name=viewport]"); viewport.setAttribute('content', 'width=1000px, user-scalable=0'); }
I used this in my submission for the CSS-Off, to ensure that the viewport specified for mobile devices didn’t also restrict the iPad’s version of the site.