My sister and I have been talking about this trip for years, and it's finally a reality! It is also my first trip off the N American continent, but I'm trying to be realistic about how much I can include. I have 3 weeks--one week in each country--Iceland, then Norway, then Stockholm and southern Sweden. We have some set commitments, but I'm wondering if it is too much to try to add a couple days in Copenhagen at the end? Also--any other tips about places and things to do in these countries? I've been reading the RS book about Scandinavia, which has been very helpful.
With three weeks, you have the time to see a lot in Scandinavia. But there is absolutely no rational reason why you allocate a week each (or any equal number of days) to those three countries. Not every place is equal. My family spent three weeks in Scandinavia two years ago and it was fantastic. We saw the capitals of SIX countries, but our time in those countries was certainly not equal.
Iceland; a wonderful place for those who want to do something unusual, but for the average traveler who just wants to see more conventional experiences, a 1-2 day stop is adequate. There are a dozen or more organized tours designed specifically to show you several of Iceland's greatest attractions in about 12 hours.
Sweden; has Scandinavia's most beautiful city - Stockholm - but the rest of the country looks a lot like rural Minnesota and Wisconsin. I'm not saying it's bad - I'm saying you would be devoting valuable vacation time visiting Minnesota and Wisconsin farm country with Volvos and folks speaking Swedish.
Norway; Oslo is more interesting than people here think, but most of it can be seen in two days. The fjords on the west coast are stunning, and could easily consume a week. It's also the best place in the world to go above the arctic circle, especially to the Lofoten Islands area where in early July you can watch the sun at 4 AM with temps in the 50's and 60's F.
Denmark; Copenhagen is a lovely city and worth 2-3 days, including quick side trips to castles nearby. There are other interesting cities and small towns to the west, but the attractions are rather low key.
Finland; The often neglected Scandinavian country shouldn't be, and doesn't have to be thaks to the cheap, fun and easy ship transport between Stockholm and Helsinki. See the RS book. Helsinki is lovely and worth 2 days.
Estonia; Tallinn is an easy ship excursion/day trip from Helsinki.
Send me a message if you want some more information.
Ending in Copenhagen makes good sense. You can probably get a much better flight home from Copenhagen than Stockholm (and save money too).
Catching a ferry to Helsinki, Tallinn or both is convenient and a good way to spend a couple days. That will require you to reduce your time at other places. There are overnight ferries that include lodging (or sleeping on deck if you prefer it).
I was going to respond, but I'm having trouble coming up with anything beyond what Randy has already said. His advice is excellent. I have not been to Iceland, so I can't comment on how much time you should spend there. A week in Norway would be wonderful. I could easily spend a week in Stockholm if it included day trips to Helsinki and Tallinn, which are both very worth while. But I do think it's a good idea to try to spend two or three days in Copenhagen even if you have to shave some time off Iceland or Stockholm.