Updating RDS snapshot export into S3

Question

We have some data in our Mysql RDS, which slows down our application, but it's no longer needed. So we want to remove old records but keep them somewhere so our Data Engineers can run analytic queries.

I've backed up my Mysql RDS instance into S3 and connected it with Athena. It works great. But if I remove old records from my DB and we will need to repeat the process in the next 6 months, our analytic team will need to query two DBs to get the data. Is there a way to make it simpler for them and update S3 snapshot? Or maybe we should use something different, Hive?