If you feel you are ready to take the DAT, then take it and get done with it.
Remember it will take 2 to 3 weeks to get your official score to AADSAS.
I applied in July but took the DAT two weeks ago. So far I got two interviews for January. Those two schools were willing to accept a copy of the unofficial score report. Other schools I applied to only accept official score report.
So also check with the schools you applied to. Some have late interviews.