I have a similar work situation--4 days a week, pumping 2x a day. I'm in the process of weaning off the pump right now. Once DD turns 1 year (in about 2.5 weeks), I'll try dropping down to 1 pump. Yesterday, I forgot part of my pump, and wasn't able to pump all day, and it did not feel good! Obviously not quite ready to stop pumping yet, but I do think going down to once a day will work out well. As soon as I can stop with once a day pumping, I'm done! Can't wait to 'hang up the horns'!!
I'm not too worried about my supply as I've not had issues before and it seems really common to wean from the pump and still be able to breastfed at other times. I hope I'm not an exception!