Ok , well I live in Göteborg by the sea ( Gothenburg ) so we have quite a lot of winterrain mixed with subzero temp , I belive we have longer winters then you but our lowest temp usually stays around -10 celcius , last winter I recorded -12,5 during a Januari night , I may buy one palm ( 150 cm ) if wife agrees...so my biggest worry is winterrain combined with sudden coldchocks that is subsero temp for many days.

Maybe I should opt for a somewhat rainsafe place ( like backyard ) with less sun and not go for the best sunny place but with less rainproctection ?