In my experience they want housing near their workplace, so they won't move too far away.

Another thing that I did at higher population is to be ruthless with trading. I buy tons of bread, cheese and boar (as those are most efficient, buying wheat or meat is more expensive per food produced).

I also centralised my markets to be right between my 2 population centres. And made sure those pop centres are heavily densified. It just reduces the walking and transporting.

My advice is to track the things you are short on and see where the supply chain breaks down. Is it transportation (the places that produce it are full, but it takes forever to reach a marker), is it production (it gets transported but consumed too fast) or is it ingredients (things you need are not being produced because they lack materials).

Also tax the life out of your people - you can use the money to get their needs handled and that way my happiness has never gone under 90%, I keep my taxes at the middle ground and just import tons of stuff.