I actually tried this at the dealer when I considered purchasing it because I had my doubts. Rolling it up basically converts it into a small carpet roll that is too wide to fit behind the 3rd row seats, and while I didn't try to fold it in half, my gut instinct told me that wasn't feasible at all -- too thick rolled up, and too big of a cargo space loss. Folding it up would also probably cause longevity issues. I just remember that mat was way bigger than I expected after rolled up. So that's why I opted for the 3rd row only mat, with zero hassle and zero cargo space loss. When I recently did a large Costco shop, I stowed the 3rd row, put the cargo mat on top near the back -- all the big items like toilet paper went up to the back of the 2nd row, while all my perishables stacked neatly on top of the protected flat area. Also have done this on garden shops that were too big for fitting everything behind the 3rd row which had roughly 50% more cargo space depth over the same mat over protected flat area, if that makes sense.
I highly recommend the 3rd row cargo mat, and total thumbs down to the 2nd-3rd row cargo mat. Unless you plan to keep the 3rd row flat at all times because your using your car as some sort of work truck or pet delivery system. But if that was my case, I would have gotten a F150 with supercrew -- great 5 seater with more rear legroom than the Explorer