Also keep in mind (for any car) that wind resistance, and hence the energy required to overcome it, increases exponentially
with speed. In other words, to go twice as fast, you'll need more
than twice the energy. This is why, in your EV, all other things being equal, range is greatly diminished the faster you go, and greatly improved the slower you go.
This may seem counter-intuitive having driven gasoline cars all your life, where mileage is better on the freeway (going faster) and worse in the city (going slower). But, that behavior is a product of gasoline engines using less gasoline at lower RPMs (higher gears) when cruising at freeway speeds. Likewise, reduced city mileage is a testament to how inefficient gasoline engines are when running at the higher RPMs (lower gears) typical of non-freeway driving, with overall lower cruising speeds, frequent idling, and increased stop/go cycles, all of which are very inefficient for gasoline engines. (Btw, that last point is why hybrid cars like the Prius use their electric motor to stop/go instead of the gasoline engine.)
In EVs, however, there are no gears (there is usually a fixed "step down" gear box, but not the typical automotive transmission). The motor is simply driving the wheels "directly" -- and the RPM for the motor has a direct, linear correlation to car speed. Electric motors are very efficient in general, and efficient through most of their speed range, and are also the most efficient at the higher end of the range. That said, it is still the energy
required to push the car through the air (overcoming wind resistance) that is the overwhelming factor limiting EV range (aside from the battery capacity, of course).
My point: There is nothing more effective for increasing the range of your EV than simply driving slower and reducing the wind resistance (second to perhaps driving on the freeway with an 80 MPH tailwind).