In reply to galpinos:
How big is your family and how big is your car? When I was kid we went for three week holidays in Spain camping, but because a big family frame tent then were so heavy my dad always used a trailer. We also had a two burner calor gas grill that had its own metal 'wire' stand that also had shelves on it to keep food. I seem to remember it looked liked a small version of the larder at home - god only knows what sort of food stuffs my mum was pack - the entire spice rack maybe? Anyway, it was just a huge amount of stuff and I remember it taking the best part of day to set up the tent when we got there and take it down again and pack before driving back north!
I've never been arsed with all that with my family. I guess the first camping trips we did when my two older kids were little were driving from Finland to England for summer holiday there, so we generally stayed only one night at a campsite - except one in Denmark where we would stay for two and visit Legoland for a day! So lightweight kit worked well. Since the family has grown to five of us we have bought a bigger family tent with inner tents and so on. But it still packs into a sort of suitcase sized bag and we can get it up in maybe 20 minutes so you can use it for just a night. For years I've had one of those single burner butane stoves that pack into a plastic 'briefcase'. They are stable, easy to use and the butane cartridges seem easily available everywhere. Camping Gaz make them but non-brand ones seem super reliable and cost little, I've seen them in Aldi and BM bargains in recent years. I sometimes chuck in a little backpacking stove like my Pocket Rocket and canister for that too. Occasionally you might want to boil water for spaghetti whilst frying up the bolognese ingredients, or I use a little stove to make my morning coffee when no one else wants one.
By keeping things relatively lightweight like that in recent years we've done 'touring' trips staying for a night or a few days before moving on, or last year when we couldn't decide where to go so booked a site for a week in the Dordogne then a site a few hours away in the Massif central for another week, with five us in the car and all the camping (and some climbing!) gear packed in the boot of the car and a small roofbox. Maybe a twin burner stove wouldn't really add to that, but I guess you need a rechargeable gas bottle for it? And maybe a stand too? I guess it all adds up.
TLR - those butane one burner stoves for less than twenty quid that come in a plastic briefcase I've found work well for my family camping holidays.
P.S. I don't know if it law but it seems that on many French and Spanish campsites now many people have separate kitchen tents, because I suppose the fire risk is serious camping inside the main tent?