Sophia is right, Whitecliffs is about 20km from Darfield, but unlike the Darfield - Chch commute (straight clear roads), the 20km from Whitecliffs to Darfield isn't straight and trickier to drive (nice drive though!).
I'd guessimate the commute to Chch from Whitecliffs at around 1 hour to the Western outskirts of Riccarton and, at a push, the airport. To the CBD I'd add on at least another 20mins in rush hour in and out. Next time I'm in the area I'll time it!
These are the timings I'd allow if going in for a meeting at 9am.
Public transport..
... sorry, not round here - shanks' pony or the car/horse/tractor/quad bike/ride on mower/kayak/skis/jetboat
Darfield would be your local township where there's all the amenities you need to get you through between "big shops" at the supermarkets in Chch or Rolleston, plus medical/education facilities etc.