Set up a client-friendly blog without a CMS template

Hey! I’m working on a project for a client who expects to be able to update the text on their site through the editor. It’s meant to be an ecommerce/portfolio site, but they have requested to add a blog. Has anybody figured out a way to accommodate a blog on a non-CMS template or will I just need to post their blog posts manually…? Maybe there’s an integration somewhere?

Thank you!