Good for you on making the decision :) I continued to breastfeed my DD when I went back to work after 1 year. The first two "transition" days when she was in daycare and away from me for 4 hours, I felt a little engorged but my body just adapted without me needing to do anything (I didn't express at all). Up till that point, she had basically nursed on demand and I guess for completeness, I should mention that we were co-sleeping, so night-time nursing too.
I didn't really do anything to prepare her, but just let DD dictate the 'schedule', and it was more than twice a day (I, too, assumed it would be last thing before daycare and last at bedtime). Mornings before daycare were not so much a problem, but she definitely wanted 'milkies' when I came to pick her up. Her daycare at the time was very supportive and I guess it helped that I picked up closer to closing time so there were less people around. The daycare director offered her office if I wanted/ needed more privacy. It was great to be able to reconnect with her after so many hours apart.
The nursing mother's body is amazing in terms of adapting - DD would nurse more often on the weekends and it was fine (though I guess she was getting less milk and more comfort then). She drank water at daycare and we gave her some diluted juice at home. At one point we gave her Pediasure Complete (since her paediatrician was pestering us about her having weight gain issues), and we tried chocolate milk, too. All to no avail - she never really drank milk, though she did enjoy using a straw sippy.
DD breastfed until 27 months (I weaned her) and she's now almost 3 years old and still doesn't drink cow's milk!
Good luck with the 'transition' and enjoy the extended breastfeeding relationship!
