I think something similar to the BMW I3 Rex would be a good solution for most
people.
70-80 miles on batteries (less lithium, less weight) would work for the
majority of people 90-95% of the time. For longer trips you switch over to the
onboard generator.
The main problem with the I3 Rex is
A large part of the popularity is due to the laws in the USA.
Powered three wheeled vehicles are considered "Motorcycles" by the Federal
government and most states, so they don't need to meet the safety requirements
for cars.
Three wheeled bicycles are specified by federal law as bicycles (over
