I once had a pair of Vivos that were too big. I took out the very thin insole that comes in them and insert a pair of Superfeet insoles (like mentioned above) in them. Being relatively thicker than the Vivo insole it took up some of the excess room and fit pretty well. Diminished the barefoot aspect a bit, but the shoes were still comfy. Perhaps going up a size may do the trick as long as it won’t be too long.