When you check in, see if seats 9B& 9C, or 9D & 9E are open. These will get you back to a two seat option. They also have extra leg room. The drawback is no window.

Are there any rows open? You can also book an aisle / window in an open row and hope nobody books the middle seat.

As other's have said, there is no other way to upgrade an award seat without redoing the award.