I predict that EV trucks with a range extender will do very well in the US, and will be the catalyst behind the move to electric trucks. Once people get the experience of an electric truck they will love it, but the option to dump in gasoline and drive 400 miles without charging is an imaginary barrier that stops most customers from giving it a shot.
Personally, I would love to see an electric truck that can be charged while driving by an external generator, possible mounted to a trailer.