make-shift greenhouse

Jennifer, I have a phal that is recoverring inside a plastic bag "tent". This one is also in its pot, because like you I don't like to disturb any of the remaining roots. Drench the plant with fungicide, pot and all, let it drain, then put it inside the plastic tent. Like Uncasteeb said, a few holes on the bag for circulation, and put the "tent" away from direct sunlight. Open the bag and check your plant every few days. I hope this helps, good luck.