I am planning on doing NIN in late July- traveling from Oslo to Flam, taking the fast ferry to Balestrand where we stay for a few nights and then back to Oslo to fly home. I looked at the Flam railway site and it appears there might be difficulty booking for July 25 at the times required to make the Myrdal to Oslo train. Is this indeed the case? Should I be worried and change the itinerary to continue on to Bergen via the fast ferry and depart from there? Please advise. I know in many cases whats available online isn't always all that's available. I greatly appreciate your help.
I would continue on to Bergen. Plan to spent a night in Bergen and return to Oslo by train. The Hardanger Vida is quite scenic. And Bergen is worth a visit.
I don't know much about how to book for the NIN - hence the reason I'm here - but I do know you can't book more than 90 days out from your date of departure. Does that help?