I have a 2x2 fort that's very successful. It's peaceful, luxurious, happy, and has almost everything a dwarf could want (as long as they don't want wood). I brought along enough wood to make more than enough beds, too. This is a fort that could probably exist for a thousand years without the slightest difficulty. There's only one problem. It's too far from civilization to get immigrants, or even traders. We don't even get goblin sieges or kobold thieves. (I did get a 'Thief! Protect the hoard!' thing once, but there was no kobold thief on the map, I couldn't find anything stolen, and that was 5+ in-game years ago.)
All this may have something to do with my having picked a site surrounded by terrifying wastelands. I don't know, do caravans and migrants take that into account? Anyways, it feels weird to abandon a beautiful, busy fort like this, but it's getting a bit dull. Anytime I want to expand anything, I think about how my dwarves are all insanely wealthy already and I have enough spare capacity to house twice as many dwarves in just as much opulence. Anytime I try a huge vanity project, I quickly realize I haven't nearly got enough workers.
I mean, I'd give a royal throne room to any peasant who came along and just hauled stuff for me. Should I abandon this fort, or is there something I can do to up the population?