We have been several times and dislike long ferry journeys
So we Chunnel to Calais, through Belgium, Netherlands, Germany (Hamburg is a pain) , Denmark (we have explored all the islands and they’re splendid, worth a journey for themselves) across the 2 spectacular bridges into Sweden. Then head up bypassing Gothenburg to get to Oslo. Turn left and explore. We then found our way to Nordkapp, across to the Russian border at Kirkenes. Down through Finland and its 100,000+ lakes. Ferry across to Estonia, Latvia, Lithuania skirting past Kaliningrad (Russian) into Poland, down through East Germany and popped into Czechia, and back out again, then France and back to Calais. Love it.