Or...
Consider rolling out a few updates at a time, with testing in between throughout the year.
More time for beta testers + more stable product with less frustrations for end users.

Another HUGE reason for doing it this way is somewhat in line what Gordon Scott had mentioned:
"What's interesting is that I've quite often started over and complete the better way in a tiny fraction of the time the original took."

It is astonishingly true and I think it could apply to BIAB in some way. Meaning, when you doing some deep structural changes and not being pressed by time, you can find other perhaps much better ways to do other planned things.