I am going to Norway in a few weeks, and part of my plan is to go for a hike around Finse (bad idea this time of the year, I know) while travelling from Bergen to Oslo.
Can I buy an NSB ordinær billett from Bergen to Oslo, take the first Region outbound in the morning, leave the train in Finse, go for a hike and take a later train (the latest train that day? the Region that leaves at 01:34 the next day? a train two days later, in case I find a reasonable sleeping spot in between?) and continue my journey to Oslo?