After 3 weeks in 50 F, fermentation was not over. It began after warming up. I racked to a secondary fermenter and let it finish fermenting in room temp.
This yeast tolerates cold temp as low as 50F but its speed decreases considerably.
I'm currently using it in 10 c (50 f), after three weeks it's still fermenting! No bubbles but the wort is active (I can see gas bubbles going up). I want to raise temp to room temp for a day see if fermentation will stop.