Hi Rico,

Our theme is based on Bootstrap grid system. You can't control the width from the Theme Options but you can use CSS to control it.

For example:

@media (min-width: 1400px) {
    .container {
        width: 1400px !important;
        background: red;
    }
}

If you're looking for professional help in this matter, there's always someone available for such tasks on the WP Kraken or Envato Studio . Pricing and timeline are always straightforward there and that's the main reason for recommending those services.

You're welcome Rico Roijé!

Have a great day.