I don't have a Wollemia nobilis, but people here in metro Phoenix report they do fine if well-watered and kept from the hottest afternoon summer sun. Of note our soil and water are very alkaline and they don't seem to mind. I have read Phytophthora is a denizen of acid soils and that Ferocactus, large barrel cactus native from Arizona to California and far into Mexico, are suscepitible to it under acid soil conditions whereas they are never attacked in the ground here. So perhaps keeping Wollemia slightly alkaline would help prevent Phytophthora root rot in cultivation. Leo Martin Phoenix Arizona USA