We ran the first part of the Varnhold exploration last session. My players, surprisingly, decided to push through and explore the entire village -- including stockade -- in one day. I had assumed they'd explore the town, retreat and regroup, and them come back to the stockade fresh.
That said, the actual assault against the spriggans has the chance of being drawn out into a loooong, relatively boring encounter. Most of the spriggans' SLAs won't function against 7th-level PCs (Scare can't affect them, and Shatter won't work against magic weapons). In the end, it comes down to rogue-tactics or enlarged, try to do more damage than the PCs tactics. Not the most exciting encounter.
So, halfway through, I upped the ante a little bit. As the module suggests, I had Agai kick over the barrel of oil and set fire to the building (with four or five spriggans still inside, no less). He made a comment about the PCs not being able to save those inside, and we stopped the session there. I'm adding a family of fisherman that avoided the original Vanishing because they were fishing eels out of Lake Silverstep (these fishermen will be the same that later supply the Eel Bake quest). They've been captured by the Spriggans and are being held in the first floor bunkhouse.
So next session the PCs have a bit of a problem: Agai is going to run, the building will be on fire (I'm using the rules for fire in the "Catastrophe!" section of Council of Thieves), and a minute or two into the encounter I'll have the building start to collapse (using the collapsing building rules from the same section). I don't expect my PCs to have any trouble with these spriggans, but adding the environmental hazards, a rescue attempt, and a fleeing BBEG should divide them and make a boring encounter a lot more interesting -- especially since they'll have to move fast or get creative if they want to explore any of the rooms inside the blockhouse.
Not exactly an addition, mind you, but I thought it warranted commenting nevertheless. Next up -- the Nomen (and hopefully Dudemeister's Trust additions!). ;-)