Hi, just come back from Tromso, with another company, single type beginning with S.
Tromso is a nice place but not a great deal on offer, yes the brewery, polar museum, lots of bars, walk across the bridge both ways for some great views, and the Artic church.
Sadly the cable car is not finished yet, met two swiss guys who are rebuilding it they said its at least 3 months behind.
Hope you are luckier than us, missed the northern lights, if you can get to somewhere away from the city to see them, not sure what the JY tour does on its visit. And be warned some parts of Tromso, off the main streets are very icy, if you have shoe grips, take them, or get them there. The main streets have heated pavements so not a problem.
Enjoy