In spite of what I said in my last post, I went ahead and booked a place in Copenhagen (or København, as I've already come to think of it from playing Ticket to Ride - Europe, or as Cathy and I refer to it, The Train Game). I am staying with what seems to be a nice couple, Julie and Nikolai, arranged via Airbnb.com.
They and their place have gotten excellent reviews, it looks nice from the photos and seems to be in a good location right across from a canal, and the price was reasonable (for Scandinavian capitals).
This leaves Helsinki as the only place I don't have a reservation. My friend Mary is thinking about meeting me in Helsinki for those days. Mary is of Finnish descent (or as I like to tease her, she is Finnished), and she's never actually been to Finland. So that would be fun, and I'll hold off on making a reservation there until she decides.