Wasn't it in civ 2 or 3 where the mid-game settler built a city that started at size 2? Or in 5 I think there was the civic that I never used that had new cities start at size 3? It would be really nice if they could find a way to do that reliably late game. Even if it was something as simple as fixing the trade route mechanic, where instead of manually assigning routes, every city simply started with a default trade route that would always supply it. So early game, that just gives you 1 food and 1 cog, for example, but if you build a city late-game, you start with a much larger base of food and production to get the city up to speed. In my current game, just built some new cities in the late industrial, and even building my special district was supposed to be 50+ turns. Trade route cuts it down by half, but it shouldn't take that long to get a city up and running, even building it that late.