Alaska Cruisetour Land Excursions

I'm doing an Alaska cruisetour with Princess next year and the land excursions just opened up and I was wondering if anyone had any advice on these. The specific tour I have is 2 nights in Fairbanks, 2 nights in Denali, 1 night in Mt. Mckinley and 2 nights in Kenai. The tour already includes excursions on the full days in Fairbanks and Denali. I will probably add one for the full day in Kenai.

But the main question I have is should I try to squeeze in excursions on the travel days? For most of them the timing seems really tight or it goes through lunch or dinner time. I guess I'm trying to balance wanting to experience everything with wanting to relax after traveling. If yes, any recommendations on ones that I really don't want to miss?

Alternatively, what can I do on my own at these places?