I want to book a cruise to Alaska in June 2023 and Skagway and the White Pass Summit train is a must. It looks like the train was running this year (just not into Canada) and looks like it is open for next year, but I'm not seeing any availability on their website. Is there a way to make sure it isn't sold out (via cruise ship excursion) before I book a cruise? Since Glacier NP is also a must, we will either be on Princess or HA.