Pre-FEED planning - PMO support

What support does your PMO provide at project setup? I was hoping for a poll, but no such luck. What I'd like to know is how you initially determine your project duration and initial estimate. Actually, I'm looking for the step or two after you receive the Project Basis or initial release for feasibility study(ies). Does the PMO provide any templates? Do you use Microsoft Project/P6/other planning software during the initial feasibility study. Any software at all? What support does the PMO provide? Don't expect an answer to all of these questions, but I would like to start a dialogue.  I'm trying to determine how useful P6 could be at initial planning (pre-FEED). Thanks.