Impossible to say how difficult you'd feel it is, I can only say that personally the northern roads seem pretty OK to me, and certainly worth the journey. The roads aren't like say the Amalfi drive in Italy, nor some of the Madeira roads - these can really be terrifying, cut into cliffs with shere drops immediately adjacent to the road. The North Corfu roads are much gentler, although there are some spectaluar views and no denying that they are at a fair height, but as far as I recall there aren't many (if any) shere drops by the road, usually a reasonably wide verge/pathway then drops down a faily steep tree covered slope to the sea.
As said before, key thing is to take it easy, and stop when you want to look rather then get distracted. Very beautiful part of the island though - worth the effort.