The drop in range will depend on how efficient your heater is & how cold it is outside. Some of the EVs have resistance heaters and they can use quite a lot of juice. Some of the EVs have a heat pump and they use relatively little juice. BMW i3 – resistance heater (heat pump is an optional extra) PSA EVs – heat pump Kia/Hyundai – heat pump in the UK market The largest drop in range is from the lithium batteries being cold.
Not sure which one our Outlander PHEV is, in addition to the electric heater apparently when the engine is running it has a 4 way valve which provide heating.
Today we went out weather wet outside temperature 12 C heater set 22 c, aircon off travelled 19 miles with 3 miles left at the end of the journey so 22 miles on pure electric, that quite a big drop from 32/33 with the heating off.
I am going to study the manual and pre heat the PHEV from the mains using the APP
Unfortunately I have suffered a brain injury and occasionally I get confused and often say the wrong thing.