Skye template: Linking blog thumbnails to source URLs?

I saw a few similar questions on this, but no clear answer —

In the Skye template, I'm looking to link my thumbnails directly to the source URL for an article rather than to an empty blog post on the site. I could technically just redirect all of the blog post URLs to the articles I want to feature, but that seems messy. Is there a better workaround?

I did email Squarespace and they confirmed that this would require custom code, and was not possible with the template as is. I don't really want to swap templates, but if that solves it please let me know which you'd recommend. I'm open to ideas! :)

Here's a link to site: https://reed-plums-7kft.squarespace.com/