It will be fine, ok head gasket can be a problem, but they dont blow "for fun". even if it did go, its repairable with a new style multi layer gasket .As for room, I have no problem with my 25 td and a roofbox, it tows trailer and carries roofbox as well as wife 2 kids and a labrador. All cars have faults if you look hard enough, I for instance wouldnt have a zafira diesel, kiss goodbye to that baby when the pump dies at 100k....
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.