Seems like 6.5M final pre-sales. Interstellar had a 2.5x PSm while HP had 2.11x. That gives a range of 14-16.5M ($2.15-2.5M) OD.
Saturday pre-sales are higher than what usually films have, but looking city wise data, Shanghai, Beijing, etc have higher pre-sales on Sat than Sun. Now that could be people basically booking IMAX shows in Tier 1 cities. That would explain the low PSm than usual for re-releases.
Ideally those Sat PS would mean a much bigger Saturday than Friday, but let's see. Going with ¥44-54M ($6.8-8.5M) weekend prediction.