Thanks. Might have gone a bit overboard with all the stuff I included :V.

I think the time the adventure takes depends on how the group wants to use it/approach it. If they just want to find some treasure/information and find a safe way into the main building, then it can take as little as 1 or 2 sessions. If they want to explore everything/deal with with the faction situations, then it can take quite a long time, somewhere between 10 to 20 sessions (depending on how the encounters go). To get the most out the adventure, I'd say it takes 6-12 sessions, with multiple expeditions to the adventure site and back.