I'm considering running SoG to the 3 players I've managed to gather so far.
I found the guidelines for adjusting battles very easily, but I'm not sure what to do regarding all the different kinds of VP accumulation throughout the adventure.
Given there's one less PC to try and accumulate points how should I adjust? Change thersholds, roll opportunities, roll results? And how?
For research, reduce the targets by 25% to compensate for reduced number of actions.
But you don't have to, there is plenty of margin already built in so that the players will succeed on research.
For my group of 4 PCs it is mostly just 1 or 2 PCs that do research at all, and its hasn't been a problem.
As long as someone is doing it it should work out.
With preparation points you can give them a bonus equal to 1/3 of what they have once winter starts.
Run an NPC for the 4th player - it's not difficult for research only. The way this adventure is structured, every PC should be contributing.
Pay attention to the topic of this thread, too: https://paizo.com/threads/rzs4un90?SPOILERS-Book-2-Researching