Hallo OS,

as you surely have seen in the maps, on a tour form GB to Martigny cycling the Alps is only voluntary, rather a nice detour. Martigny can easily be reached from the Lac Léman (Lake of Geneve). In French hilly regions and middling mountains very steep roads are rare, exept at the southern slope of the Massif Central. In relation to England roads in similarly hilly French regions are less steep.

Yours sincerely

UL