We've never won the Gates of Arkham expansion, and I've played with four or more players 5 of the six times played. The base game, even with the Unseen Forces, and Grave Consequences expansion, is much easier, as we've probably won twice as much as lost out of the numerous play through over the last couple of years.
I haven't played inn a while, and only played the base game. But based on that, couldn't you have tried again the last task by discarding a dice (and optionally focussing the 2)
At 17:35 . Since you have 4 dice left, if you loose 1, one still have a small chance to get your 8 investigation
I don't know if this matters, but didn't Skids lose sanity as he rolled 3 terror in in his two rolls?
terror effects only happen when you fail to complete a task. At least in the base game.
Great game!