At the end of World War II in Europe, German troops still held almost all of Norway. There were still several hundred thousand German troops there, though the units with substantial combat power had probably for the most part been combed out and sent to more active fronts. Some German commanders in Norway apparently thought about fighting on after the official surrender, but were quickly replaced by people willing to follow the surrender order.
What if they had tried to fight on? Maybe Hitler decides in late March/early April to make a last stand there and transfers material, men, and key scientists there as parts of German are overrun. Maybe he even goes there himself.
Obviously the Germans aren't going to hold out in Norway long-term, if for no other reason than the fact that they wouldn't have an industrial base to keep their army supplied. At the same time, if the Allies have to gear up for an amphibious landing, that would take time. They would rush the issue as much as possible because the Soviets would be moving into the north of Norway (as they did historically).
An interesting aspect of this: Norway would end up with a lot of the German scientists and exotic technology/prototypes, at least in the short term. It would also end up with its infrastructure devastated by the fighting.
Would the German rank and file fight on in these circumstances? Against the Soviets, yeah. Against the west? Hard to say. With Hitler there and an influx of hardcore Nazis, they probably wouldn't have a lot of choice.
How long could the Germans hold out in Norway? Not long. I would give it maybe three or four months at the absolute most, and that mainly because of the time it would take the allies to gear up for a large-scale amphibious landing. Three months would put the end of the battle for Norway into early August. Maybe they collapse a few days after the Japanese surrender.
What do you think? Plausible? Any implications I'm missing?