Hi Mags,
If you can part from your van for a night i can recommend the Dulyn Bothy, a mountain hut not too far from Conwy.
Information here:
http://www.mountainbothies.org.uk/bothy ... othy_id=98" onclick="window.open(this.href);return false; but do follow the Bothy code.
Failing that the car park closest to the bothy is very remote and guarantees wildness. But beware of short steep sections on the drive up, they can be avoided by a long way round, but these are welsh country roads were talking about.
Hope you have a wild night out somewhere.
Paddy