Range is an important consideration, because the basic purpose of a vehicle is always to carry you from point A and point B in the fastest and safest possible manner. Even the latest electric car still has relatively limited battery capacity and this could put a limit on the overall range of the car.
If your longest travel distance with a car is 20 miles, you need an electric car that has a range of at least 50 miles, instead of 40 miles. This will allow you to have a safety margin. Unfortunately, the route of your trip will never be a straight line. You may need to travel through winding roads and go uphill. The condition of the road and extreme weather will also affect the energy utilization.
The availability of many fast recharging stations should also determine your buying decisions. If the number of fast recharging stations is quite numerous, then it is relatively safe to choose an electric car with somewhat shorter range. If you are unsure about the ability of the car to reach longer distances, you should consider choosing an EV with small internal combustion engine as an extender unit.