Thanks Fatani for enlightening us...
My very conservative and cautious worst scenario guess:
For October 5th draw, I guess cutoff would be CRS 481-483 with 1,300-1,500 ITAs.
For October 19th draw, I guess cutoff would be CRS 480-481 with ~1,500 ITAs.
For November 2nd draw, I guess cutoff would be CRS 478-480 with ~1,600-1,650 ITAs (there has never been a draw with more than this number of ITAs before).
After that, things can return to normal (read: pre-May 2016 scenario). A total of 4,500 ITAs may be issued in these 3 coming draws according to this speculation, thus clearing out the build-up of candidates with a score of 481 and above. InshAllah.