Not sure what your budget is and time schedule there is another option besides carrying extra batteries which are expensive there is also foldable portable solar panels just a little bigger then a brief case will charge most ebikes 4 to 5 hours the catch expensive also .plus the cargo room factor or another option a pit stop motel room to charge up you and the bike but I feel we're u are coming from that's the adventurous sprit ,but great post very cool just the ideal of contemplating such a trip is awesome