Dahua Hotel is no good, it's only four stars, and although it is near the lake, it doesn't have a large lawn. First, the West Lake State Guesthouse or Xizi Hotel, both of which are close to the lake and have large lawns, and the scenery is quite good. Originally, they were villas of prominent families in Hangzhou. After liberation, they only received domestic and foreign leaders, and now they are also open to the public. Secondly, Shangri-La should be ok, with a large area, facing the West Lake with mountains on its back and a large lawn, but I don't know if it meets your size standard.