@GeorgeS - I believe this query has nothing to do with QuickSight, rather a generic Athena related question. In that case, I believe your data pipeline should have a piece of code to run glue crawler to add/update the Athena schema to ensure that new partitions are automatically reflected in Athena. You can perhaps go through the below link to get a better understanding.
Add Newly Created Partitions Programmatically into AWS Athena schema