I'm a UX Architect for a fortune 500 company and I have a very big portfolio to manage, so i'd firstly say this is a UX question not a Project Management question as it's a fair question to seek in a forum like this.
My approach thus far.
- Create a UX Repository of Excellence. You running around chasing down team(s) to see what they are up to isn't going to scale. The teams need to trust you but also be aware of your value, so you in turn need to de-mystify the magic of UX. Create a central repository that breaks UX into the patterns "Here's 10x tab controls, here's why/when/how tab controls are good/bad and here's some research around them" then follow up with a form or social commentary (transparent) that asks the question "Disagree? tell me more..." (creates a two way trust / challenge point). Basically you want to provide everyone you're co-working with with more "I know" vs "I think" answers, and a honey pot like this will do what I call "passive evangelism"
- Be the band manager not the rockstar. I used to be an Evangelist for Microsoft and I learnt years ago that everytime I was on stage presenting, I was failing at my job. I needed embedded experts to be on stage on my behalf becomes it creates "trust" with the audience, so the analogy of being a band manager not a rockstar held. Rockstars come and go but good band managers always scale. In your case find and unroot the officers in your Ux Army and have them be advocates on your behalf, get them to be your eyes/ears in the agile sprints etc that the various teams you have in your portfolio of project(s). Help them, train them and embrace them as they will always be your best agents of change anyway and you come across as a persona who "works well with others" which breaks down the whole "us" vs "them" mentality (which reduces ongoing UX solicitation meetings anyway).
- Create a Brag Wall / Update. At Microsoft the quickest way in 2007-2009 to get a promotion was to pat yourself on the back out loud, its shallow and weak but it worked. Turns out in corporations people are like that at times, shallow and want to feel as if they mean something than just a payrollID. Create a "brag" point and make others around you envious of the attention that your UX focus has given, make them want to be part of your program of awesome, and so praise the work they do (which in a way is you praising your own work). Point is amplify the successes of UX moments (not talking about "We just shipped") but tell people what's amazing about how the UX and your team(s) relationship is having on the work ahead.
Example. During Windows 7's creation, every week we'd get a
newsletter explaining that weeks' research about they found in
ongoing usability studies for its new UI. There were some amazing
and facinating insights that would usually get burried in some
sharepoint site traditionally. Yet each week I found myself waiting
for the latest insight into what success/fail looks like in a
product like Windows.
Interview people aswell, get them to talk about how Ux has helped them see differences in the way they think/act/smell/laugh .. GeekStories are brilliant motivators at times as people usually go "I didn't know that...". (did you know Windows Start button / menu was first created as a place holder. The dev at the time figured they'd come up with a menu eventually..so..menu was created in the meantime. Fast forward today, they finally got around to fixing/removing the menu in Windows 8... and turns out ...people did not like that at all). You just got served a Geekstory :)
In Summary
You're not managing a portfolio, you're managing people who work in the same portfolio as you and despite your god-status in the developer enclosure you must act like a passionate and caring god...you must heal, feed, clothe and embrace your disciples while at the same time bring people along for the journey of that which is our beloved Ux Vudu Magic! (if only they knew we were all frauds! hehehe ..shhh don't tell them!)