North...
Yes, have flown there many years with and without sophisticated electronics. Before the days of GPS, navigation was based on use of compasses set to True headings and alignment was set with the use of a special sextant mounted in the aircraft's windows (Sun/Moon/Stars). The use of the sextant was part of the Commerical Pilot's license in Canada.
We used a procedure called 'Desitnation Grid' where we would 'offset' the gyro compasses to the destination airport meridian. This could lead to a huge discussion on its own.
No restriction on 'going over the top', in fact I've just completed a Polar Trial demonstration flight for an international operator. The test flight will have a flight track right over the North Pole.
As for the Magnetic Pole...it moves around and its exact location can be found on Nav Canada publications.