The only way the Watchtower is going to survive is by adapting to the new generation and making big changes. If it does live on for 100 years more, it will look different than what it is today. We live in the Information Age and each day it is easier to record information for future generations. One big problem with the Watchtower is time. They've limited their time so much in the past that their predictions (or prophecies) have failed and they're forced to change.
As for 1914, I can only see this doctrine abandoned far into the future. Slowly being insignificant. There's so much invested into that one date that to undo the damage is going to take a loooong time. Not to point out how this would prove opposers right and them wrong. Only time can tell what will happen...