I am on this same cruise, had it booked since Nov 9, 2018 while on board a Celebrity sailing. We also have a pre-cruise 9 day land portion on our own. Last week I cancelled private excursions with no penalties, and already the money posted back to the credit card. I even cancelled Celebrity excursions and the money also was returned and posted to my credit card. We had 2 AirBnB booked and the Seward location has already cancelled all their bookings thru the summer. Therefore all the Seward booking money including the Air BnB service charge was returned.
We though about completing the land portion and getting this experience checked off, then complete a Seattle Alaska round trip another year. But believe Delta will probably adjust their schedules, meaning our flights may not be there. The cruise insurance from a 3rd party provider hopefully will be returned when Celebrity cancels this cruise.
Once the cruise is officially cancelled, I will seek a cruise refund, have the Delta award tickets return to my sky miles account, and process a refund request on the cruise insurance, and have the host cancel our AirBnB so the money is returned,. The host has already suggested she will do the cancellation. Least I not forget cancelling the Hertz rent a car. So, at the end of day I am out the $89.99 for purchasing the Alaskan TourSaver online app and the 4 Perks at a great price along with the booking onboard credit. We still have a glimmer of hope to maybe consider the land portion, but that will be a game time decision. Sorry for the long post but I hope my decision making may help others.