This is a very good plan! I will try it out. I have an electric pump and recently bought a manual pump too for work use (As manual pump is smaller, easier to carry and can pump quietly in toilet 'in case of emergency'), after seeing your post I am happy that money won't be wasted.
I work from 8 - 6 (sometimes longer) very hard and busy work. Now seeing your plan, might try:
6am breast feed
7:30am arrive at work, electric pump
10am morning short toilet break, manual pump
12-1pm lunch hour, electric pump
3pm toilet break, manual pump
5-6pm before going home, electric pump (or manual pump if extremely busy)
at home evening, breastfeed till night time before sleep.
Still not yet working but I hope by time I start work baby no longer need night milk !!