Jquery scroll distance, depending on window size

I am trying to write a scroll event that stops a few pixels above the target container. I do however, want that to only happen when the window size is less than 800px.

Sort of like an if condition or a media query where the distance from the anchor depends on the window size.

Now this is the code I'm using (found in another thread):

       function offsetAnchor() {
       if(location.hash.length !== 0) {

       window.scrollTo(window.scrollX, window.scrollY - 120);
   }
 }

 $(window).on("hashchange", function () {
   offsetAnchor();
 });

// This is here so that when you enter the page with a hash, // it can provide the offset in that case too. Having a timeout // seems necessary to allow the browser to jump to the anchor first.

window.setTimeout(function() {
   offsetAnchor();
}, 1);


$('a[href*=#]:not([href=#])').click(function() {
     if (location.pathname.replace(/^\//,'') == this.pathname.replace(/^\//,'') && location.hostname == this.hostname) {
       var target = $(this.hash);
       target = target.length ? target : $('[name=' + this.hash.slice(1) +']');
       if (target.length) {
         $('html,body').animate({
           scrollTop: target.offset().top - 120
         }, 1000);
         return false;
       }
     }
   }); 

As it stands with this code the scrolling stops 120px above the anchor. I want this to only happen on window sizes below 800px though. Made some attempts with:

      if($(window).width() < 800)
      {
         window.scrollTo(window.scrollX, window.scrollY - 120);

      } else {
         window.scrollTo(window.scrollX, window.scrollY - 0);

      }

But it does not seem to work.

Any help would be much appreciated.