In truth, just about any yeast will work just fine in cider. You don't need to rehydrate in my opinion.
I wonder if the 50 degrees quoted above is Fahrenheit or Celsius. Personally I ferment my ciders close to 50 F and would not recommend doing so at 50 C!
Also personally I don't use any nutrients but I know most cidermakers recommend it. Poo on them. My ciders are better than theirs. ;D