The question kind of depends on what training you are doing, levels of fitness already achieved etc. In terms of what Charlie did, the general answers are in the Forum Review Ebook/Print Book.
The answers are something like:
6-10 races (have to check this one)
This depends on how much volume you drop but in my experience probably a week or so before you need to start reloading… but why would you want to be fully peaked any longer? You can perform at a high level for quite a few weeks even before a taper.