Just to make sure we're talking the same language first: ensolite is the plastic-fronted black neoprene, usually in robin's egg blue, right? Not the white popcorn-like sprayed on stuff with the yellow-ish foam on the back.
I needed to repair a small section (kitchen backsplash). Because my kitchen's at the front, using anything else for a backsplash was out of the question - there were too many curves. After much frustration looking for substitutes, in a flash of brilliance (*blush*blush*) I found a piece in the closet that was the EXACT size I needed (with an extra 2-3 inches to spare). And, lucky for me, because it was in an awkward spot (under my fridge), the original installer was a bit lazy and only used a few dabs of rubber cement to tack it on. I figured I needed the ensolite more on the backsplash than in the closet, where it couldn't be seen. If you only need a small piece and can't find any, perhaps you have a spot in a closet or cubby that would do for you?