This year is already half over and there are a number of large events already scheduled. Notably a papal trip to Asia and Oceania (2 to 13 Sep), papal trip to Luxembourg and Belgium (26 to 29 Sep), the Synod (2 to 27 Oct), and the start of the Holy Year on 24 Dec.
So that leaves November and most of December available.
All that follows is pure speculation :-)
I think the most likely date is Sat 7 Dec (just before the Feast of the Immaculate Conception).
The announcement of the consistory has generally been 1 to 2 months in advance. Since I suspect that some of those attending the Synod might be on the list, I don't expect it before that concludes on Sun 27 Oct.
The following week there are several opportunities. The Angelus on Sun 27 Oct, General Audience Wed 30 Oct, and the events around All Saints and All Souls.
Note that on 7 Dec there will be 121 Cardinal-electors (out of 236 total), assuming no deaths. While that is above already the limit of 120, that limit has been widely disregarded in the past. See Cardinal Electors and Modern Limits for more details.
Here are some other posts and links that might be useful.
- Cardinal Stats and Charts
- Cardinal Electors and Modern Limits
- When does a Cardinal become ineligible to Vote in a Conclave?
- When does a Cardinal become a Cardinal?
Some Cardinal links to the main site that might be useful:
