Just to bring closure to my own thread -- I've now booked us on the Viking Magni for fall of 2023. Cabin class AA, Veranda Suite, which is in the middle of the ship and thus should be as quiet as anywhere. Booked business class air through Viking. I found out about something called "air deviation", which is only $100pp and lets us schedule time before and after to book our own hotels, though we lose the airport transfers. And I bought Viking's insurance.
Thanks to all for your help.
Thanks to all for your help.