Can recommend Treloan Farm on the Roseland: http://www.coastalfarmholidays.co.uk
Photos on the website don’t do it justice – in a quiet and relatively undiscovered bit of South Cornwall, 3 decent and almost deserted beaches within a half hour walk. They allow fires as long as they are off the ground and offer fire baskets and logs.
Short walk to Porthscatho for the pub. Possible to get to St Mawes and even Falmouth by ferry without using the car.
Great sea views from the site – they even have a mobile wood-fired pizza van which comes to the site a couple of times a week.
Another Cornwall option is Henrys on the Lizard – very quirky in a great location and allows fires in braziers. Loads to do in the area too.
http://www.henryscampsite.co.uk
In Wales, this is one of our favourites, handy for sea and mountains, and really wild feeling location. May be outside your 5 hours though:
http://www.caedufarmholidays.co.uk/campio-camping/4585004218