I think I've seen twice where people have failed the Winter Event because someone accidentally triggers the Forest Wave by walking to the forest, without actually having the intent to trigger it.
I would like to recommend that in order to trigger the Forest Wave, someone has to talk to the NPC and click "Trigger the Forest Wave." That way they have to actually intend to trigger it rather than just walk inside of the forest.
Or we could make it so that it only triggers if 3-5 people are in the forest, rather than just 1 person.
Of course, we could say that the players should just not enter the forest, but we've seen the event triggered by people who don't know the mechanics; this will just remove a lot of user error at no cost of the mechanics/communication necessary for the event.