Answer: Wilting due to overwatering usually happens when the overwatering is chronic and causes root damage. I would not really expect one overwatering episode to cause that.
Sudden wilting on an otherwise healthy plant as you described can be due to exposure to cold. If this is what happened to it, it should recover over time -- the cold damaged leaves will drop and it will grow new ones.
Since you were able to keep it healthy and happy for four months, returning it to the original spot sounds like a good idea. Keep in mind it has to be protected from both hot and cold drafts. In winter it may need less watering than it did in summer when it was growing faster, use your finger to check the soil and see if you need to water.
If it does defoliate, you could also take the opportunity to cut it back if it needs to be pruned. I'm sorry about your plant. I hope it is okay.
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