The flexible deadline is the same for everybody, obviously.
We originally suggested a hard deadline of the end of December, but since people found that too rigid, let's try for having all the I-Ds available by mid-January at the latest.
that the deadline is at "the end of December" with the maximum flexibility of "mid-January at the latest".
If you have changed it, announce it well before the real final absolute deadline. We also expect that the announcement is accompanied with explanation on why we have much time to analyze proposals with the shortened period.