I think Regina needs to reemerge with the Evil Queen and then maybe her and Robin could find happiness together.
Just before Regina removed the cover from the cage, when she acknowledged that the Evil Queen was part of her, I figured that that was the key to ending the separation spell, and I thought “Aha! The cage will be empty!”. And then it was empty, and I was happy that a character was showing emotional maturity and moving on from a tired plot thread. But sadly, nope…