I wasn't sure how the inline accordion is set up, as it's the same code that was originally created for Joomla and actually didn't need any changes to make it work on WP; so I asked one of the Joomla developers.
Apparently even the Joomla version doesn't automatically resize, but the CSS you'll want to adjust is very easy:
In the css/template.css file, around line 1679:
.ac-container input:checked ~ article.ac-large, .ac-container2 input:checked ~ article.ac-large2 {
height: 230px;
}
Just adjust the height as-needed.