It cannot be stressed enough that the amperage/volt range is very affected by temperature range will start to drop off as the temperature drops below 9 degrees , as you move below 4-5 degrees it’s drops off a cliff below around. 2 degrees this is then also heavily affected by the number of stops you make. During the part of the winter where it hovers around zero you will be stuck getting mid to high 20s in terms of range , as the battery is thermally controlled (and it appears engine) a lot of power will be used to heat the battery , and the if you use it heated seats and then if you use it heated cabin , heated rear window.
if you are getting 3 miles a kWh you are doing well ,it’s no unheard of to loose .5kwh just turning the car on and pulling away Without preheat.
the recommended trick on this forum is if you are going to go beyond battery range epically in the winter always start on petrol to heat the car as heat is a free byproduct of the ice , the car will carry on using the residual heat of the ice when you switch back to battery to complete the journey on electric and will give you maximum electric range however range will still be depleted as the battery heating is never replenished using power from the battery.