Not sure if you need this or not, but if you are planning on staying in hotels,this will save you money in Norway. Their hotels are everywhere.
http://www.flyertalk.com/forum/hotel...ends-rate.html
We did a trip to TOS TRD and OSL in winter for leisure and
northern lights viewing. It was a lot more expensive than we imagined, and we used elite extra baggage for food. We booked the train tickets well in advance and they were unbelievably affordable.
KL flights to OSL are always 99E from AMS so if DL miles are the only option at least get to Schiphol. I think you will find SKs network to be easier for connections though.