Shipping Calculator on Product Page (without items in / adding to cart)

I deliver products locally and I’m using WooReer to calculate shipping based on distance.

I’m trying to get the shipping calculator working on a single product page without having to add the product to the cart. At the moment, I’m using a shortcode to display the calculator on the product page, the problem is it won’t show up unless there is an item in the cart:

function shipping_calculator_fn() {

ob_start();
WC()->cart->calculate_totals();
echo '<div class="cart_totals">';
wc_cart_totals_shipping_html();
echo '</div>';

return ob_get_clean();

}
add_shortcode('display_shipping_calculator', 'shipping_calculator_fn');

Does anyone know of a way I could trick the calculator into thinking there is an item in the cart? I’ve looked into how other plugins and it looks as if they create a ‘pseudo’ cart to calculate off, but I can’t for the life of me figure it out.

I’ve also tried to wrap the calculator in the native cart_totals wrapper in the hopes of a magic ajax refresh, but as you could probably guess it was unsuccessful.

Everything actually works after you’ve added something in the cart, albeit inelegantly.

Any help would be appreciated.

Cheers,`