Lisa,
I think that one thing that happens as you get further into expressing (whether it is for work or for EE reasons), is that you get more gung-ho about when and where you express (similarly to public breastfeeding).
I just used anywhere in a parent's room with a power point - not worrying about the cubicle; similarly any old empty room at work, or sitting on the floor in a quiet bit near a power point when at a meeting - with a big jacket people are going to hear and know what you are doing, but they won't actually get an eye-full.
I really admire your persistance!