According to the website:
9-22°C (48.2-71.6°F) ideally 12-15°C (53.6-59°F)
I typically use this yeast at 52° and it works great. I would be concerned about the yeast not getting the job done and maybe going dormant at that low temperature. I would probably warm it up but people do stuff all the time that I don't and still make better beer than me.