The primary way Hillary loses enough for Trump to pull ahead is if Assange releases some vicious details, solely about her. If he had anything game-changing though, he would have released it by now. Absentee/early votes already started. Even if he releases, MSM other than FOX news may give it only one day cycle and just bury it.
If he had anything that would stick, he would have released it by now. I'm not ruling out a late "leak" which turns out to be overblown/made up, but sounds bad enough to hurt Clinton and can't be disproven in time for the election.