We are talking Europe and not the US, plenty of stops but watch out in France on Sundays as only self serviced open and they take French credit cards.
(so much for us "being in Europe"!).
I used a card at a french pump on sunday............
The mileage depends on what gearbox you have.
I rode back with shapeshifter from morocco, both riding along at the same speed for approx 1300 miles.
He has a an 1150 ADV gearbox with the low first and fifth gear , i have a standard 1150 GS with an adv tank. At the same speed he was doing 500 RPM's more than me.
Everytime we stopped for fuel he put in 5 litres more than me. That's a lot of extra fuel over 50k miles.
And here's another thing - if you run out of fuel, lay your bike right over on it's R/H side onto the rocker cover, and you'll get another 12 miles of fuel
