I wish I could say that winter kill on washingtonias was rare here as well. They are easy to kill here when seedlings. I have killed my fair share for sure. When they are a little bigger though, they seem to be pretty easy to protect. They just grow so quickly that they jump back to life early each spring even after total defoliation.
Of all of my palms though I am probably most anxious to get my 3 T. takils in the ground when we finish our new house. (followed closely by my S. birminghams) There aren't any trunking palms that are really hardy here (not in my mind at least). I am hoping that T. takil will prove to be just a little more hardy than other trachycarpus species. If so, I could feel like I have one species of trunking palm that is at least hardy here in most years. Time will tell for sure, but so far they have been more leaf hardy than similar sized fortunei and nanital in pots. (they hold on to their spears better too)
All that may be a pipe dream though. If all of them die on me in some cold year to come, at least I can keep growing vegetables...and my house is 10 minutes from the nearest boat ramp at Lake Tenkiller. So I've got back up plans if palms ever burn me out.