Everyone's interpretation of the situation and risk is different. But you can easily be in for £000's for speed only. I think they also threaten jail time, but for a country with one of the lowest rates of locking people up, I find that odd. I did see enforcement semi regularly even where you'd think you'd be safe - and my own personal experience was that in general people drive very "conservatively".Norway does have a reputation for strict and low ish speed limits so interesting that you did not find that much of an issue, I guess it is like most places and things are a little more flexible away from villages and “civilisation”. Scandinavia also has a reputation for sky high food, drink and hotel costs so it would be interesting to know how long you went for.
Looks like a fantastic trip, thanks for the post.
Not to take away from it being a wonderful trip, but it's not like France/Italy/Alps/etc for driving. My own personal feeling is that even Switzerland is substantially less likely to sting you.