I express at work like the others. Went back at 4.5 months, he's now 9 and intend to until he can get onto cow's milk at 12 months.
Like the others, with a bit of organisation, not a problem. I commute for 2 hrs each way. Take 2 sterilised bottles with me in a medela cool bag with ice block which I put in the fridge at work with everyone's sandwiches but it's zipped and sealed (although if out and about the cool block from the freezer can easily chill the milk for 12 hours). I have 2 pumps. One at home and one that lives in the office. Expensive - yes - but means less carting stuff about as I need to express at the weekend to build up milk for Monday.
We don't really have many facilities at work so I express in the disabled loo - wipe surfaces and wash hands etc then careful with the pre-sterlised equipment. Wash the pumps bits in boiling water with washing up liquid and put in a clean sterile tuperware in the fridge at work. I also, before I use the bits from the tuperware again, rinse them in boiling water again just in case.
Take pump bits home every 2/3 days and whizz through microwave steriliser and back to work, just to be safe. I was told though, especially after 6 months, that washing in boiling water in good enough. We haven't had any upset tummys or sickness so I can only assume the method works :-)
If out and about for meetings all day so not able to get to a kettle etc, take both sets of pump bits from both sets pre sterilised so I can express twice and not worry about cleaning kit bits in a client office or the many other interesting locations I have expressed in.
A bit off topic from your original question but my top tip is to buy enough bottles. I work f/t and we have 9. On any given day, I take 2 with me and he takes 3 to nursery (2 with feeds plus 1 with milk for baby porridge, started on 3 full bottles of milk until weaning at 6 months). Leaves 4 spare bottles in the fridge so I can prep next day bottles when I get home and then the used ones from that day go in the micro steriliser . It means if something happens and you forget to do it one eve, you're not scrathing round trying to get bottles ready whilst getting ready for work.
Good luck.