@Andy Skinner When you create your workspace that will be tied to your databricks account.
your account will be tied to subscription and resource group .
from E2 architecture you can create multiple workspaces (in different regions) in one databricks account
https://learn.microsoft.com/en-us/azure/databricks/getting-started/
one more thing you need to consider is unity catalog --> data governance can be done within multiple workspaces in same account and region
