Shopify Mega Menu Dynamic Columns

Hi,

I'm looking for somebody to help with changing our mega menu on our shopify store to dynamically change how many columns there are depending on how many items are within the main category.
I have attached some pictures, the main one shows how the categories are now which is always 3 columns but in the 2nd picture it shows a category with only one item in it which still has the white space of 3 columns making it look out of place. So we would want it to shrink down to the white space of 1 column instead.

Let me know if you need any more information on this.

Thanks