Thanks for the reply. You also open up another question I had...Well, if you want to average > 20mph then your best choice is a class 3 ebike. With a class 1, you will not be using the motor much at all. Honestly, I believe you are probably fit enough to be able to average close to 20 mph on a non-electric road bike with dropbars if you can average 13 mph on a fat bike.
I am not sure what Stefan's point was and English is not his first language. However, Stefan has a lot of experience with very long distance rides on ebikes and can give good advice for extending the range of your battery.
If I am able to sustain 20 mph at a lower assist level with a Class 1 bike, would that not give me a greater range than if I rode 22-24 mph while the motor works harder all the time on a Class 3? Put another way, if I "topped out" a Class 1 bike 20-30% of the ride, I should save range compared to riding with full-time assistance on a Class 3 bike? Does that make sense?