Alex. We went to AK last year, 7 days Vancouver to Anchorage.
Rather than do the ship’s overland tour I booked one myself via a US travel agent, which proved to be an excellent decsion: we went more places, it lasted longer and we also got to spend extra days in ANC.
I also booked my own flights, LHR/YVR return, and ANC/SEA. This enabled us to have a week in Seattle; we then got the train back to YVR and home.
Always book the best cabin you can afford. Most people – normally those in inside cabins – say it is not worth the extra cost as you do not spend much time in it. THEY ARE WRONG!