It's all about the string gauge. I've gone down to drop-B and drop-C on my Les Paul. I've even done GGCFAD.
For drop-C I can get away with 52-10's, but I prefer 54-11's. I just got a set of Ernie Ball Beefy Bottom, Slinky Top.. which I am digging quite a bit.
Scale length doesn't really determine what tunings are possible. But it does determine the overall tone. Loads of people are going lower than C# on their Les Paul guitars.