I get antsy at 200km, even though it's good for more.
To be honest though, we've got it easy. Back in the days when I was a bit younger and there were no credit cards you could get stuck with no petrol very easily. Most garages closed at 6pm and that's even if you could find one. Lol.--Nowadays with card machines in every garage you can get petrol at any time day or night.---Then you had to plan your journies or become REALLY stressed out.
City riding with loads of stop start is horrid on the fuel efficiency. I've done as little as 80 miles before the lights flash. My average is around 100 when commuting but easily 130-140 when riding on the open road only.