In this case, the "expanding div" regions is not clickable.
Ah, that div can go in a <a> (since HTML5 this is valid):
<a href="#"> <div style="background: red; height: 200px; display: flex; flex-direction: column"> <div style="flex-grow: 1"></div> <div> Go Back </div> <div style="flex-grow: 1"></div> </div> </a>
Update November 2020: I think the best possible technique for this is Method 4 in this article. The <div> (or whatever wrapper element) remains semantic