Based on watching the actions of still-in family and old JW friends I think many will stay in to simply support their "tribe" but with a LOT less time, money, and energy...much like many Italian and Spanish Catholic families I know who attend "church" a few times a year, for weddings, funerals, etc.
Headquarters has shrunk the facilities and personnel and therefore cut the red ink to a minimum. They will be able to comfortably live off a vastly reduced donation base for many years, simply selling off real estate assets as needed.