Multi-region lambda deployment with code stored in S3 bucket

I'm working on a CFN template that includes a lambda whose code is stored in S3 (due to external dependencies)

I'm looking for best practices on how to minimize the operational effort to support multiple regions (right now I need to create buckets on each region to be supported and upload the lambda's code to each bucket)

Is there any workaround/alternative to having one bucket per region?