There is some stuff in this box which you can use for the base game or the long night. (Survivors, items, ... )
But if you really want to play Warring Colonies you need to have two colonies. That's the whole idea behind it.
I can't tell if it works with only two players. I guess there wouldn't be much conflict because there are to few survivors out there.
I don't know ...
Leaving the Colonies War mode and Lone Wolf, in practice does the base game only add new survivors and new objects? Or is there something else?