This kind of palm-tree can resist -15° (as long as it is not so cold for too long).
See the tallest sequoia tree i have by me (more than 30 m high), they were here long before me, and they will be there probably long after me.
A little history:
My house has been built in the park of a 18 century castle that has been destroyed almost 30 years ago, but they kept the existing trees from the park.
In my area, most of the aristocrats who fought with Lafayette during the American Revolutionary War, bring back with them sequoia's seeds that they planted in their castle to remember the future generations that they have fought for the US independence.
And the reason why these giants are around me, is because we first fall in love of them at the time we bought our house.