Coolest temps FLF can handle?

I chopped my FLF wayyy back leaving just one old ragged leaf on the stem. I put it outside to a spot directly outside the window it was in where it never gets direct sun. In just 3 weeks it has 4 new buds and is starting to leaf out so it seems to be happy where it is! My question is- when do I need to bring it inside for the winter? I live in GA so it’s still in the 80s during the day but it is starting to cool off at night, it has been in the mid 60s at night pretty regularly. It is sort of protected against the house so the plant may not be getting quite that cold. Later this week it is supposed to be mid 50s for a couple nights so I’m wondering if that is pushing its cold tolerance with these new tender leaves.