Hi @labrumfield,
There is no option to show the sidebar in a blog post and hide it in the single page.
However, you can customize theme to meet your requirement using child theme.
You can buy Blog Way Plus from theme-forest https://themeforest.net/item/blog-way-plus-minimal-wordpress-blog-theme/19848313?ref=promenadethemes
It comes with child theme which you can use to modify single page as per your need.
You can contact us if you need further help.
Thank you.