The aerodynamic situation of a bicycle is so disadvantageous that the easiest way to get a long range e-bike is to simply ride more slowly. People internalize beliefs about energy-range ratios from electric cars, but they don't translate well to bicycles.
The exact same thing applies to electric cars, though -- going slower significantly increases your range.
It is kind of a shame that recumbent bikes are expensive and bike nerd coded. A recumbent e-bike with an aeroshell would be fantastically efficient and useful in so many situations, but if you tried to buy one today it is going to cost as much as a car and have everybody else sneering at you.
> recumbent e-bike with an aeroshell
The term of art here is "velomobile."
They're also a great way to get really badly hurt.