How to enforce a release's fixed end date?

[Michael Kogan]

Dear community,

I have created a cross-project release (CPR) with a fixed end date. However, after finalizing the scope the date of one of the projects has moved past the end date I have specified (with a red flag indication). Obviously Portfolio flexes the time edge out of the resources-scope-time iron triangle. 

How can I fixate the time edge and make it flex the resource edge? In other words, how can I configure Portfolio so that the end date stays fixed while the teams' capacity gets overloaded?

Thanks,

Michael