I"ve managed to get a working solution for now, instead of moving the endNote, I set the range for the first cross-Reference to the formatted text of the endnote, relink the rest of the cross-References to the new endnote, then delete the original endNote. That does the job, but since there are a LOT of endnotes and cross-References, it takes a bit longer than I'd like.

If there's an easy way to move the endnote (or other range) from one position to another, it would save me this extra time and complication shuffling all of the cross-References.