The Fermentis data sheet says that it'll go as low as 53.7°F but ideally not below 59°F.
This has always been a struggle for me as I serve and ferment in the same "beer fridge".
SWMBO says I can't get another fridge, so I'm left with the dilemma of serving slightly warmer than I'd like, or fermenting cooler than I'd like.
Anybody got a recommendation?