How can I constrain a row to be as high as the shortest column in a CSS grid?

Question

Please see this two columns grid example, where the image is set to be 100% width/height with object-fit set to cover. The issue here is that I would like the thumb column to be as short as the text/contents column. In other words, the row to be as short as the text column, not the thumb one. Is it possible in some way?

Here's the really basic code:

.main-link{
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.post-thumb{
  grid-column: 1 / 2;
}

.post-contents{
  grid-column: 2 / 3;
}

And for the image:

  figure.post-thumb{
    position: relative;
    width: 100%;
    height: 100%;
    overflow: hidden;

    img{
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
  }