Never knew the National Trust had sites. The only NT property we have stayed on is Tredegar House but the CAMH had this before the NT took over the house. Many of their properties have plenty of room and they could easily expand the numbers and get some more income. I would assume both clubs would be interested if they offered suitable locations.
Tredegar house is NT, but the caravan site is CAMH. I am not sure, but I think the land is owned by Newport council.
John