I would suggest you add Finland and Tallin to your itinerary, if you have sufficient time for your Scandinavia and Nordic adventure. Last August, my husband and I flew from LA to Stockholm and spent 4 days exploring the city. We stayed in a wonderful and not too expensive, Airbnb. We always follow Rick Steves books on how to get around the city and save on getting into museums, etc. We then boarded the Viking Ferry to Helsinki and booked a buffet dinner with window seat and it was the most amazing smorgasbord, I've ever seen. I also booked a room on the ferry and made mistake of getting the least expensive one. Turns out that our room was located underneath two floors of cars that were parked on ferry. I was a little upset about the room, but it was clean and had nice towels and bedding and both my husband and I slept great on our bunks. The best part of being on that ferry was leaving Stockholm and cruising through the Swedish Archipelago! I grew up in Seattle and lived on Puget Sound and this was over the top beautiful. We spent two nights in Helsinki and explored the city and dined on salmon and berries at the outdoor market. One night, we took a Airbnb experience cooking class and learned how to make Finnish meatballs, salmon soup and cardamon, cinnamon rolls. The city is beautiful with pastel buildings with a skyline dominated by the Lutheran Church and Russian Orthodox church. Wonderful old style cafes and design shops and museums.
Our next stop was taking the Viking ferry to Tallin, Estonia and we booked another Airbnb for two nights. The city looks like something out of Disneyland, but is real! The Occupation Museum is a must for every American to go see and experience! After two nights, we took the Viking ferry back to Helsinki and then boarded a train to Turku. Spent two days in Turku exploring and then boarded a train to Oulu. Oulu is my ancestral town of my mother's family. Two weeks before our trip, I made contact with a relative and we were able to meet up with our Finnish family. Truly amazing and they even brought us to the church in Haukipudas, that my great grandparents were married before they boarded a ship to the United States in the late 1800's. Spent two nights in Oulu.
In Oulu, we rented a car and drove up to Lapland and stayed in Rovaniemi. In Rovaniemi, you can visit with Santa Claus, postmark your Christmas cards to be sent to your friends and family at Christmastime, see and feed reindeers and explore the area.
Drove back to Oulu and boarded a flight to Copenhagen and spent four nights before boarding a cruise ship that took us to Norway, Scotland, Ireland, across the Atlantic to Halifax and on to New York City.
The Viking ferry line was inexpensive as they operate casinos and duty free shops to keep costs down. The train from Helsinki to Turku and on to Oulu was about the same price, I paid for my husband and I and our two grandkids to go on a ten minute train ride from Santa Barbara to Carpenteria and back to Santa Barbara on Amtrak. Key is to book in Advance. Same with flight from Oulu to Copenhagen on Finnair, so reasonable. I am biased but found Finland to be magical!