Caravan Heaters

sunshinetours

Electric blankets are a good idea. Decent quality ones that have an overnight setting. Pointless trying to heat permanently and older static (no central heating indicates and older van) to me

Have a fan heater with 1 or 1.5kw setting and use that to heat up bedrooms just before bedtime and maybe then on a timer just before getting up time in the lounge living area

27col

Caravans don't get cold at night because they are "near the coast". They get cold because they are both badly insulated and ill heated.
All electric heating appliances use the same amount of electricity, the only reason for choosing one as against the other is convenience of use.
Once you work out what your heating priorities and timings are, you can then decide what type of electric heating appliance will best suit your usage pattern.