WI the RN home fleet was mostly in position in the Nth Atlantic/Norwegian Sea on 7th of April 1940 when the German forces sailed to invade Norway? And they managed to successfully intercept the seaborne invasion forces, which included the 2 battle cruisers, 1 heavy and 2 light cruisers and 14 destroyers between Bergen and Narvik? These wouldn't be too much of a problem for the home fleet if they were caught early, before the luftwaffe could assist this far north.
Is it practical for the Germans to capture all of Norway by land from the south? Of could a line be established in the narrow part of central Norway? Would the Bruitish reinforce France to little effect if they were holding northern Norway? How would the destruction of virtually all of the heavy units in the German navy affect the war? Would it allow the RN to concentrate elsewhere like the Med if they don't have to mark the S & G?