I feel like this is maybe a little bit unfair. For the length of the actual motorway itself, the M11 isn't actually too badly serviced by fast chargers. There are fast charging options at Cambridge Services, the Birchanger Services (these one's, admittedly, are shite) just off the Harlow exit for the A414, and then a new hub at the Redbridge Roundabout as you come off at the bottom, they're all 150Kw options aside from Birchanger I think. I live just off junction 5 and run an i3 and even in the cold, I have no issues getting up and down the M11 in a car that will only do 80 miles at motorway speeds in the cold and rain.
Eco mode doesn't really do very much to actually preserve the battery in most cases, it just dulls the pedal responsiveness and makes it easier to drive more economically. If you're not driving the car economically in eco mode, you're not going to get an economical result. No, you'll never ever see that car do 217 miles. Not a chance. But without conceding too much to the economy gods, I'm not having that you can't confidently complete a 100 mile trip and there's no way you're ever only going to get 50 out of a full battery unless you accidentally go commuting with your lead boots on.
Eco mode doesn't really do very much to actually preserve the battery in most cases, it just dulls the pedal responsiveness and makes it easier to drive more economically. If you're not driving the car economically in eco mode, you're not going to get an economical result. No, you'll never ever see that car do 217 miles. Not a chance. But without conceding too much to the economy gods, I'm not having that you can't confidently complete a 100 mile trip and there's no way you're ever only going to get 50 out of a full battery unless you accidentally go commuting with your lead boots on.