I have use it al 62 degrees, use 2 sachets and went from 1,051 to 1.009 in 5 day, i was surprise, rack to secondary and ramp the temp to 65 for two days, keg and lager for 28 days.
It is great, has a little worry because of the fermentation temp was over the manufacturer range, but now i now that works well.
Cheers