Yeah I really dig Retreat as well. It's awesome.
Love the old city concept. It is something that has cropped up quite a bit in the game from Hawk's point of view. It's more defensible but also full of it's own dangers. It also provides some strange resources which is pretty interesting.
Doc seemed to know the way to one, but both Solomon and Hawk have pretty good maps for old cities. Solomon's are more relevant to the region surrounded Crosspire while Hawk has stuff for out West.
Hawk does in fact have hundreds of refugees from down south, ex Paradise Slaves including farmers, religious types, crafters and maybe some fighters. It's possible (likely given this game) that there are bad seeds hidden amongst them too. But yeah there could be some opportunities for new PCs in there.
FWIW, It would be cool to have a game which was less intense everyone wants to kill you and more character and town building. A PC social political games rather than a world politics game. If we are moving to a new town it would be great to establish the relationships of the people there before 10 buckets of hell come after us again. Of course the next game is probably not for a long while yet but I like to think it's no so far away really.