The Cities Skylines 2 map will be five times bigger than in the original Cities Skylines 2 builds.
You will have nine tiles available when you begin in Cities Skylines 2, but in the base game, you will be able to expand this to a huge 441 buildable tiles. Building height restrictions have also been lifted, and you can purchase tiles of variable size and terrain – and also variable building space – whenever you choose to expand.

Colossal Order says that the Cities Skylines 2 map is five times bigger than the map in Cities Skylines, representing a full 159 square kilometers. "That's bigger than some countries," the developer says. New features also mean that, when starting a new city, you can select whether it is in the northern or southern hemisphere and what kind of climate and weather it is likely to be affected by.
In the meantime, check out the full management games available now.