You could embed your web font inline to the stylesheet, as base64 encoded data url.

    <style>
      @font-face {
        src: url(data:application/font-woff2;charset=utf-8;base64,...) format('woff2');
      }

Your page loading times will obviously take a hit, but that'll give you pretty close to 100% certainty that the font will be used, should you want that.