EHU solution is by far the best and safest option ... it also opens up a wide range of other uses ... charging all those electronics, electric kettle, hair dryer, toaster, cooler/fridge etc etc
We have used an oil filled rad when camping in UK, and it was brilliant ... no noise (fan), and can be left on a low setting all day if necessary.
We use old fashioned paraffin bowl fires, pressure lamps & stoves in the tent when camping & a portable CO detector - never succeeded in making it go off. I don't have a Degree but self-taught in common sense. I grudgingly use a EHU for the fridge in hot summers (abroad) but may dispense with that now I'm happier getting the thing lit on gas. The car would suffice for the 'rechargeables' , towels for wet hair etc. The more electical appliances the less it feels like camping for me.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.