I just came across this view for portfolios:
Milestones progress instead of tasks. I cannot believe I have missed it all this time.
Absolutely brilliant and makes more sense when presenting to stakeholders at this highlevel of the portfolio. On the progress tab, simply click and change view from tasks into milestones. What you will get is a beautiful milestone progress (red and green - i.e. late or complete).
oh the little joys in life