Good morning!
When you say you created the installation package, did you also create the server-side task to deploy it as well?
Under the deployment task you should see listed under install two options- one to deploy the package to remote machines, and the other to generate a setup package.
If you pick the second option, it allows you to specify the path you want for the file.
This should allow you to be able to set where you want the file to be, and then you can move it somewhere else for your GPO install.
Hope this helps.