Driving at 1 MPH less top speed would make way more difference from a practical standpoint than slower acceleration. Acceleration rate is somewhere around #50 on the list of things to extend the range of the vehicle.The most fuel efficient way to accelerate which will give you a higher m/kWh which will give you more miles is to pretend there is an egg between the accelerator and your foot. Keeping the energy use light green will also help.
I read on here about people complaining about not getting at least 259 miles on a charge. If they would drive more efficiently, they would easily get that and more. I don’t charge to 100% anymore since I don’t need the distance or miles, but I would see 350 miles when my m/kWh was in the high 5s or higher.