It is still resorbing water and nutrients from it, so let it decide when to jettison it.
To save that plant, I'd do the following:
- Immerse the entire plant in warmish water containing 1 tablespoon of KelpMax per gallon, letting it soak for a few hours.
- Nestle the base into loose sphagnum that has been moistened with that same solution.
- Invert a clear plastic bag over the plant and pot to trap the humidity, to slow further desiccation.
- Keep it shady and very warm, watering as needed when the moss is nearing dryness.