The coldest we had here so far was a brief 22F and it did not damage the plant, but it was kept dry. I think as long as the plant has already managed to form a hard bark it is able to handle the colder temps. But if your plant still has a green caudex, better bring it indoors.
I have also learned to move some plants much closer to the house when there is a frost advisory. Then particular to ponytail palm, I make sure to move it back to the sunniest side of the garden the following day and keeping it dry if possible. Our mild winter is more on the rain side, so my ponytail palm has lots of pumice in its media too, so if it happens to rain, it always drains fast.
Here it is by the way
it's a great plant to also keep inside . A hard frost could damage it.. Or you could care for it inside . Keep it inside under bright grow lights for green plants. It will continue to flourish or keep in under the eaves outside wrap pot in straw or bubble wrap outside protect from hard frost.
