I came across this situation once. My solution was very creative.
Both cables came in from below. Both were AC cable, in internal clamps. There was no slack in the wall, and no access from the basement.
I cut open the sheetrock, since they were planning a new backsplash anyway. I connected the two cables into a duplex connector, screwed that into a rigid coupling, which I secured to a 4x4 box with a chase nipple. This gave me a 1.75" rise, without compromising the grounding, and left a whopping 4" of conductor in the box, which I pigtailed to a GFCI.
Not ideal, I know, but what else can you do?
