Ran this at an adventuring league meetup over eight hours with a full table of six level 2's: Fighter, Sorc/Warlock, Rogue/Warlock, Barbarian, Bard and Tempest Cleric (me) and a level 4 Paladin. The DM was a pro with decades of XP. I spent my gold on healing potions to pass out before we set off. We barely survived. If the sorcerer didn't land a natural 20 against Agrak it would have been a TPK for sure. Two of our party members got charmed (one by the Incubus, the other by Agrak). My tempest Cleric got KO'd by the charmed barbarian. Everyone was tapped out and a hit away from death. Apparently the other table running this adventure killed the Incubus, but by the time we encountered him we were already in bad shape.
It wasn't all razor's edge though. The fight against the scarecrows went ok. The goblins on mastiffs at the cave entrance got put down pretty fast. We managed to stealth our way into the mushroom cavern and the bard got close enough to put 3/4 of the goblins around the first toad to sleep, someone managed to frag the last one. The Rust mosnters could have gone a lot worse. Wearing chain mail I was indifferent to the pleas of the Zhentarim who wanted to capture them alive but we managed to subdue 2/3 of them. I didn't have mending so people lost a bit of armor and weapon value. Lesson learned.
The big
up was in the goblin living quarters/beast pen cavern. We climbed the roof of the big beast pen after tying a rope to the metal bar 'barring' it when the goblins surrounded us. We pulled the rope to remove the bar but the beasts hadn't emerged yet and the Goblins were volleying arrows at us so I cast sanctuary to climb down and open the doors to the pen. The giant boar emerged and while I was hoping it would run amok and trample some of the goblins, apparently the Barbarian and Fighter had other plans. They jumped from the roof and tried to mount the abused, ill-tempered and enraged wild boar. Because somehow merely getting on its back will turn it into a willing mount... for reasons. Needless to say, the big boar followed by the regular ones in the pen were all like Orlly? and the Barbarian got gored (he lived because, hey I'm a Cleric, that's what I do). In retrospect, I should have cast fog cloud at prone level on the roof so the party could stand, make a ranged attack then drop prone into concealment, the beasts would have opened the door on their own we just didn't know that they hadn't due to initiative order being kept secret'ish.
If anything the whole experience has convinced me to rebuild as a Life Cleric. Sure I'll be a glorified walking medicine cabinet but in these large parties of partially unfamiliar players I think it will pay off to specialize. Frying people with Wrath of the Storm was fun (and I saved the Paladin with a channeled maxed out WotS against one of the toads). The utility spells are interesting but perhaps situation dependent whereas the Life domain spells are often ones I would want to prepare anyway. My Cleric is a Hill Dwarf so I'm not even losing the martial weapons I carry other than the heavy maul for when I'm out of spell slots. I can still swing the hammer for 1d10 instead of 1d8 at that point anyway. Besides, my buddy is playing the bard, so he can do the battlefield control a hell of a lot better. He has more kills from insulting people to death with vicious mockery than I do from cracking skulls.