Been 22 times Alaska, not carnival or Norwegian
best trip is RT Vancouver port, time in port important, arrive and depart. You should do 28 glacier out of Whittier, Juneau has 8 hour excursion if in port by 8am and don’t leave till after 5pm. Balcony is great but you will be missing what is going on other side all day long, cure is to plant on area of viewing inside ship that lets you see both sides, then go out for photos etc, warmth is also great. Skagway is nice if there early and leave late, train-so so, good experience but more of outdoor is private excursion up the canyon and beyond ,maybe even to Carcross and beyond,too much to tell you, have to have a couple hours over lunch to give you the plus and minus of trip. Leaving Seattle is too long out to sea, no inside much there