Enter Lauren staring at this for a few days, thinking of how I was going to alter the loop and make it big enough for the button.
SERIOUSLY.... Then I had an AHA moment. Change the button silly! I went to my button stash. Found several small buttons. I picked one
Pulled out my seam ripper and removed the button
Sew the new button on and TA-DA! It fits. And now I have my shirt back to wear, before fall and winter comes.