The intresting thing for me in this fight, is the how the diffrence between clinch-based takedowns and single/double leg takedowns will work.
Aldo's single/double leg TDD is just impeccable. It's downright godlike. And even if you manage to take him down his sprawl is nearly as good, meaning he will pop back up even if you hit the floor. Only when he's very fatigued/hurt and you set up your shots with strikes (which Khabib isn't that good at) does this type of takedown become even remotely applicable.
The clinch is a different game though. While Aldo likewise has superb TDD here, he does become entangled in them in a way his single/double TDD doesn't, where he usually sprawls free. This mean that Khabib would have time to work his myriad of techniques, and use his size and strength to wear Aldo down. Basically, Khabib has a much bigger chance in the clinch than he has on the shoots.
Khabib's wrestling style is very cardio taxing (both for him and his opponent), since Khabib is an expert at placing his weigth on people, and hauling them down while they're trying to get up. Since Aldo's cardio is one of his "weaknesses", then if Khabib manages to score early takedowns and apply his grueling, cardio-taxing grappling game, if could pay big dividence in the fight, since Aldo's prime would be spent handling Khabib's wrestling.
How Khabib would handle Aldo's outside game is also intresting. I see nothing in Khabib's techniqual arsenal that would imply he could deal with Aldo's stinging jabs and leg kicks. If Aldo establishes dominance at this range, he could pepper Khabib into passivity, especially in the later rounds.