Not without protection such as bubble wrap and x-mas lights.
There have been numerous "hardy" seed strains of Washingtonia robusta
floating about amongst those who specialize in cold hardy palms and subtropicals. One such strain was obtained from a specimen in Las Cruces, NM, that had supposedly recovered from a brief but harsh freeze that was -5 F. After extensive trials in many different gardens between Vancouver and Eugene, none ended up being long-term hardy in the maritime NW if left unprotected. Washingtonia
is a heat loving genus that needs a generous amount of it to thrive, even the ones planted in cool summer areas on the N. California coast look ratty from the chilly Pacific breeze during the summer.
Stick with Trachycarpus
if you want a hardy palm that's going to get tall with a trunk on it.