I was completely unaware of the issue of hireling raising the difficulty of the mission. Good to know, will try it just buffed and solo, see how it goes.
How well does invisibility work for this? Are you able to effectively sneak past and just fight at places where there is an objective you need for the quest completion or do you still trigger dungeon alert and just get screwed by that and a zerg chasing you when you do pop out of invis?