We are traveling to Norway the end of September and wanted to do the Norway in Nutshell tour. How early should we book for a group of 5? Also, any tips or recommendations throughout the tour as far as ease of travel or seat priority? Thanks!
You could go ahead and book it now. The tour is a trip on the train Oslo to Flam and a 1 hr. train ride down into the fjords. Then you ride a fast ferry out to Bergen. Or you can do the trip in reverse.
The end of September is past prime travel time in Norway as rains come in Sept. and it gets cold. We went on the trip the first of September and the weather was unusually glorious.
I don't think that it will be especially important to book ahead for the end of September. July and August are peak season. If you're departing from Oslo or Bergen, then cruise-ship travelers starting in the morning in Flam will be on a different schedule than you. You can buy train tickets or rail-pass-holder seat reservations in Oslo or Bergen train stations.
I did the nutshell tour in October. While the Fjord cruise, and the narrow gauge Flam Railway, were less than half-capacity, the main line Oslo to Bergen train segment was completely full, and sold-out. Since that train requires reservations, IMO, it's essential to book ahead.