Here is my take on the 'remaining distance'
This is forever updating, and if by chance at the end of your ride you went up a small hill, it will key on that data.
IME the battery will be the same... no drop-off until you get to 10% battery remaning, and then it might only let you ride in Eco or...
I watched the video. You will notice the rider never sits on the saddle. I have ridden hardtail with yamaha motor on aluminum frame, and it beat my rear end. 43lbs of bike, motor and battery on alloy frame with 33mm tires in the dirt?! No thanks.