The outbound relocation effect went from 57% to 90%. I suspect that 1200 samples is more than enough to demonstrate strong statistical confidence intervals. (Though I haven't run the numbers.)
That MOE would be extremely conservative given that the proportion of interest is far from p=0.5; the classical MOE would be +- 1.96 * sqrt(0.9 * 0.1 / 1200) = +- 1.697% -- but of course it's not a representative sample as you mention.