My first adventure for Legendary Games is the 7th-level Pathfinder adventure called The Horseshoe Calamity. You can get it here. I'm quite proud of it, and happy to have suggested one of my favorite artists, Marco Morte, as the cartographer for it.

It's written to plug into the Reign of Winter adventure path, but it's also a GREAT plug-in to the Kingmaker adventure path, as I just described on the Paizo forums as follows:

How much, if any, of this adventure could be appropriated to fit with the centaurs in The Varnhold Vanishing adventure of the Kingmaker adventure path? Trying to figure out if I should take the plunge into the icy cold depths of this adventure.

CB

tl;dr: All of it fits, and very, very easily.

Longer answer: I've run Kingmaker, and it's inevitable in the Varnhold Vanishing that the PCs run into the suspicious but peaceable centaurs of the Nomen tribe. There are two ways to easily incorporate the Horseshoe Calamity there. In either case, you should arrange it to be a hard winter at the time.*

First, the village of Dolanni (where the adventure begins) might be where the PCs meet the centaurs; that is, the Nomen centaurs of Varnhold Vanishingare the same as the Ovoskich tribe of the Horseshoe Calamity--pick either name. Aecora Silverfire (from the Varnhold Vanishing) and Mikka (from the Horseshoe Calamity) are both the same war-leader--pick either name. This puts the PCs right into the adventure and inserts it most neatly.

Alternatively, the Nomen centaurs know of the Ovoskich tribe a few days to the east (off the map of the Stolen Lands) and ask the PCs to look into a rumor for them: that the horseshoes of the legendary centaur Ildarik have been found there. More specifically, instead of asking the PCs to go take on the spriggans to prove their good intentions, Aecora asks them to check on the Ovoskich in the village of Dolanni instead (in this, the PCs seem like good candidates to her, because they're humanoids and there are humanoids in Dolanni). Then your PCs travel to the site of the Horseshoe Calamity.

If I'd written this adventure a year earlier, I would have inserted it in my personal Kingmaker game just as described in the first option above. (I wasn't the GM for our Reign of Winter campaign; my wife was.)

* You can set forth a particularly harsh winter during the latest kingdom turn, via a "random" kingdom event; I engineered various kingdom events to suit my narrative quite often, "rolling" the result that would create the best story.