How to change APIGatewayRestApiStage StageName in Serverless framework?

The stageName of my deployed API Gateway is being set by:

provider:
  stage: myStage

This is frustrating because I have four environments: dev, staging, qa & production each with a separate RestAPI per environment (which is fine) but I’d like my stageName to be ‘default’ as naming the stage by the environment is semantically incorrect.

How can I achieve this? Ideally, I’d like to do so without using a plugin but open to answers that involve plugins.