Seems a similar attitude to 'boy racers' who have just passed a driving test, acquire a powerfull first car and pay scant regard to any driving advice (go slower or you will kill/yourself/somebody else).
Proabably the only answer will be a painfull, serious but non-fatal (hopefully) accident or incident; hope nobody else suffers with him. Ideal would have been for him to have broken his leg on Ben Nevis and spent another couple of hours up there before "rescue".
Beside the river just down the road from me is an official 'caravan club' campsite with all mod-cons, in the village really, local pub is the Royal Oak. About a mile up the valley is a farmers field campsite (also beside the river) , short walk to the Towy Bridge pub, so probably one of these two?