Is it possible to copy RCE Reports and Dashboards from one instance to another?
If the answer is "no," are there any Community suggestions for a workaround?
Most dashboards and reports rely on activity data of some kind which cannot be imported from one instance to another. The only way to have something show up in a Marketo dashboard/report is to create the data scenario in Marketo you need to display the result. So it's more like importing the data needed to create the result in that dashboard.
Can you give us a bit more detail on your use case so we can give you workaround recommendations?