OK so if they needed two servers, here are the steps:
Create "Server C" which has a large map, but don't open it
Put the west half of the map on "Server A".
Put the east half of the map on "Server B".
Launch with "Server A", and be ready to open "Server B" if needed.
Once winter hits and the population drops, copy everything that was built on A and B onto C, and use only "Server C".