Hi there,
you have to consider every part of the design that will affect the height of that container.
First switch to mobile preview:
1. The column containing the image reduce its width eg. 25%.
2. The column containing the content increase its width eg. 75%
This will give more room for the content, reducing the chance text reflows to many lines.
2.1 Reduce the columns padding
2.2 Reduce the typography sizes and top/bottom margins of any headlines in the content.
3. You may want to consider removing the Read more button, if you have GB Pro then you can Hide on Mobile from the Advanced panel of the block.