Agent Job: Execute T-SQL on different server?
You can trigger a SSIS job from another server, no need to move your jobs. 

So you can leave your SQL Agent jobs on the database server, deploy the SSIS packages to the new ETL server and then modify your job steps to start the SSIS packages running on the ETL server from your database server. You might need to modify the 'Run As' part depending on how you set up your permissions in between your 2 servers.