Jubaea chilensis, the Chilean Wine palm, is a fairly well known palm from central Chile.  It is the most massive palm in the world, often growing a trunk in excess of 6' wide, and is also probably the world's most cold hardy feather palm.  Young plants can usually tolerate temperatures down to -9°C/16°F without harm, and older plants have been known to survive temperatures down to -18°C/0°F without damage in Montpelier, France.  It is at least as hardy as Trachycarpus fortunei, and should be hardy west of the Cascades in the Pacific Northwest, and should also be tried in milder areas east of the Cascades with plenty of irrigation.  There are at least three distinct forms of this palm: a form with beautiful weeping blue fronds, that is relatively tender, the usual form with arching green fronds, and a form with shorter, stiffer green fronds that is more common in Europe and said to be the most cold-hardy.  The only unfortunate thing about this palm is its slow rate of growth, which can be sped up somewhat by generous feeding and watering once the palm is established.