Next month, my newly-promoted wife (upgrade from fiancee) and I will be flying XN tickets from PHL-EWR-CUN. I know upgrades on the PHL-EWR flight are out of the picture, but I wanted to see if any of you can recommend how to get upgraded on the flight from EWR to CUN. I am a Silver, so I don't know if XN bookings are able to get upgraded on it at all.

I guess I could play the honeymoon card, but I figured I would check with you all to get your input.