Procedural dynamic Automatic Landscape Material Set 3 Tropical Islands

IIs there a way to double the map size (from 8 km to 16 or even 32km) I really like one map in particular but I want my game to be a Open world of sorts and I need to be able to fit a lot of different things 1. beach 2. swampy area with inner islands, 3. 1 port town and one small town with many dispersed villages.

For that reason I really like the map 4 (down)-3 (over)

Is this possible?