The plot below shows the dilemma faced by the teams. They cannot enter Italian airspace during the night.
This includes the island of Sardinia. The tracks shown are as follows (small dots are at 6-hour intervals, large dots are midnight)
Red: 500m (1500') slow track to the centre of France
Blue: 1700m (5000') Sun/Mon night on W coast of France, Mon/Tue night off E coast of north Spain, then midday over Sardinia - but when to cross mainland Italy? Coming down low over the E coast of Spain is tricky - strong Northly winds tend to flow down and off the Rhone and could sweep the teams over the med.
Green line: 10,000' - midnight over the mountains, then Mon/Tue midnight over Sardinia - not a good plan