You do know that the Nov 1st date is just some states don't you? If she wants to get her name on the ballot for all the state primaries the date would be November 1st she would have to announce by, but even in those early Nov 1st states she can still be eligible for as a write-In. Candidates do concede states all the times. Reagan did not announce until later in November.
It's kind of hard to get elected when you're name is not on the ballot, although Alaskans do seem to have a thing for write in campaigns.
Maybe it's because they are the smallest state in the country. Won't work in the big leagues.