Steph and I recently returned from the Viking Venus 'Into the Midnight Sun' cruise. It was a fantastic time. Incredible food, great scenery, great ports, great crew, and the weather was uncharacteristically nice in almost every port.
There was one smoking area on the ship, on the top deck. It was covered and sheltered, but open to the air on two sides. So if the wind was cooperative it made for a nice smoking experience.
Here's us several hundred miles above the Arctic Circle at exactly midnight: