I find it very strange how on this website the consensus is that for the Nazis to pull off an invasion 20 miles across the channel is essentially impossible but for them to assault Norway over a much longer distance, with worse infrastructure to start from, attacking into much tougher terrain, is often regarded as “lol, never easier”. The OTL invasion succeeded in spite of a laughable plan because the Norwegians were paralysed with indecision, the Brits were criminally negligent, and both were caught not just with their pants down but mid-squeeze.
If the first invasion fails then trying it again into a prepared defense with most of the kriegsmarine hors de combat would be an epic disaster.
Consider the superficial differences in operations: -
Navy: -
Britain - second largest in the world, dwarfs yours.
Norway - not quite negligible but smaller than yours.
Army: -
Britain - Mobilised as much as possible with some armour & modern anti-tank weapons.
Norway - Almost all militia, partially mobilised (or caught in the throes of...).
Air Force
Britain - several hundred modern fighter aircraft with a modern air defence system, backed by large number of mostly-decent bombers;
Norway - road hump of second-rate aircraft.
Intelligence: -
Norway - neutral, not really expecting an attack.
Britain (April 1940) the Germans will never dare invade Norway, must be a ruse to slip raiders into the North Atlantic. [Completely agree with your criminally negligent comment above.]
Britain (from June 1940) - there is only one objective for the enemy.
As you say, the invasion of Norway was one of the most audacious military plans in history and should have collapsed ignominiously, but the Royal Navy were complacent if not negligent. Whether the cost, especially for the Reichsmarine, was worth the strategic advantages is the question.