@ ptitviet
Hello!
It's not a greenline version, but a 'normal' car with the 1.2 TDI. That means additional weight and no start/stop or a lower chassis. I have to say that all of those things don't make a big difference in consumption, it's mainly the way of driving. But every bit helps!
You have already a good mileage, the Octavia is a bigger car and short and cold trips doesn't help. I love Switzerland, it's beautiful. But cold in winter and quite hilly! So try to maintain 100 km/u on flat road, overtake and accelerate during descents and slow down slightly on hill climbs. Increase the tire pressure and get a winter grill cover. That's also my first plan