Welcome from an O'Brien in Newfoundland Canada! My husband's family came from County Clare. We are going to Ireland for his retirement trip...
Now for your question... I thought like you that there must be some magical complicated way of doing this but there's not...
Some nice person just told me to pivot when I came to the turn. I did. And it worked. You just fold the material in under in the corner when you stitch the binding down on the reverse side. Works great!
Be sure to post a pcture when you're done!
Lori