The route (roughly)

So, this is the route:

• York to Dover: 270 miles
• Calais to Troyes : 246 miles
• Troyes to Tournus : 180 miles
• Tournus to Nimes : 220 miles
• Nimes to Carcassonne : 125 miles
• Carcassonne to Libourne : 203 miles
• Libourne to Civray : 104 miles
• Civray to Azay le Rideau : 90 miles
• Azay le Rideau to Rouen : 210
• Rouen to Calais : 140
• Dover to Canterbury: 20 miles
• Canterbury to York: 260 miles

Grand total (minus the inevitable 'oo look at that' detours (or, that road isn't on my satnav!): 2,068 ish miles!