This paper estimates the daily kWh responses on a working weekday of 1326 single-family-home residents who voluntarily participated in a residential optional dynamic pricing (RODP) pilot in the winter-peaking coastal province of British Columbia (BC) in western Canada. Based on the pilot's operation in November 2007-February 2008, we estimate that the kWh reduction in the peak period of 4-9 pm on a working weekday sans an in-home display (IHD) is: (a) 2.2% to 4.4% at time-of-use tariffs with peak-to-off-peak price ratios of 2.0 to 6.0; and (b) 4.8 to 5.3% at critical peak pricing tariffs with peak-to-off-peak price ratios of 8.0 to 12.0. The IHD approximately doubles these estimated peak kWh reductions. As BC residents already have smart meters with an IHD function, these findings recommend exploring the use of a system-wide RODP program to improve the BC grid's system efficiency.