Re-potting a peace lily.
Recently, my wife re-potted a root-bound peace lily and it has been struggling ever since. We have since found out that peace lilies do better when a little crowded, so it is pretty obvious that we put it in a pot that was too large. Would it be advisable to re-pot the plant back into a slightly smaller pot?
Yes, repotting into a smaller pot is a good idea. Too-large pots create a risk of overwatering and root damage, since the plant will take much longer than before to use up all the water stored in the soil and the roots may end up sitting in water. Peace lilies are susceptible to overwatering, as described in this article:
Also, please see this article to make sure your plant has the other conditions it needs: