So I managed to get them all gathered back into one spot. The "main camp" by first finding what random underground camp area where I could at least see them all. In this case, inside the goblin fortress. I simply left camp in the goblin fortress, then dismissed the party members from outside the camp. They left, walked back to camp. I reentered the camp area in the fortress, asked the remaining party members that I hadn't dismissed from outside the camp, and then repeated the action. After using this idea, I entered the "main camp" near the grove and all members were there. Hopefully it remains that way for the time being.
