We cruised up the Norwegian coast in February this year. We, and everybody else on the ship, came ready prepared for freezing winter weather with thermal everything, socks, gloves, long johns and great big thick jackets - and sweltered. We got all the snow and dramatic scenery we went for, but only on one day did the temperature fall any distance below 0C.
And remember, even if the weather outside is cold the ship itself will be grossly overheated. On the ship most of us looked like beached whales in nice warm sweaters in a ship which seemed to be heated to at least 25C.
Oh, except for DH, who never goes anywhere without an adequate supply of T shirts, which he wore and he just looked smug!