18 months after writing the net-ward-winning article Dynamically updating in the year 2014, I wrote some patches for Firefox for Android to make it possible to update a page's existing meta[name=viewport] element's content attribute and have the viewport be updated accordingly.

So when version 43 ships (at some point in 2015), code like this will work in more places than it did in 2014:

if(screen.width < 760) {
    viewport = document.querySelector("meta[name=viewport]");
    viewport.setAttribute('content', 'width=768');
}
if(screen.width > 760) {
    viewport = document.querySelector("meta[name=viewport]");
    viewport.setAttribute('content', 'width=1024');
}

I'll just go ahead and accept the 2015 netaward now, thanks for the votes everyone, wowowow.

https://miketaylr.com/posts/2015/08/dynamically-updating-meta-viewport-in-2015.html