Should I keep expanding?

I'm currently playing a large pangea immortal game as China and have run into something I haven't seen before, despite aggressively expanding to ten cities I still have 37 happiness (I got the fountain of youth, half decent religious traits, and the ability to build circuses in most cities). Normally I'm barely keeping my happiness level positive when trying to expand fast so I don't know if I should keep pushing out more and more cities until I start running low on happiness. I'm in the middle of the medieval era and have now grabbed all of the areas that offer new unique resources. I still have space for at least five more cities as my neighbours have done a very poor job of expanding.

My neighbour to the south is not really accessible for war due to their capitol having a single hex access through the mountains. My only other neighbour placed their cities in terrible positions that have no luxuries or resources which leave only their capitol worth keeping but I already have all of their luxuries.

Do it.

FOR CHINA.

No seriously, if you have good resource spots to pick and choose from, go for it. It'll pay off in the long run.

If victory is assured either way, and you enjoy sandboxing, go for it

I would keep expanding as long as there are good food tiles to allow the city to quickly grow and overcome the science penalty.

The science penalty is reduced on large maps anyway so expanding is usually worth it. I'd say build 3 more good cities and see where your happiness is at. I like to have at least 10 global happiness for any city I found later in the game (medieval or later or thereabouts). That way I can send food there right away without wasting it by plunging my happiness too low too quick.

Okay I'm going to go for it. I might try to keep around 15 happiness as a couple of my newer cities aren't very large yet. I'm closing in on being the top for land/food/production/money so if I can get big enough to grab those it should lead to being tops in the other categories.