Thanks to everyone for your quick replies. It sounds like the recommendation is to finish “as is” and let the points get chopped if needed. The quilt is about 84” by 72”, so I’m not feeling the need to add a border.
The quilt also made me feel better that there is a universal truth of UFOs: there is probably a very good reason why it wasn’t finished. As I am working through my own stash of UFOs, there is usually a problem that kept me from finishing at the time.