I am going on a tour trip with all hotels booked from Beijing to Shanghai from Oct 13 to Oct 25,2018

On Oct 25 I want to visit with my nephew who has a computer business in Shanghai and stay with him in his apartment and visit more of Shanghai for 4 days and then on the 5th day on Oct 29, 2018, return to Canada . I already have the Hotel tour trip booked and I have my Air Canada ticket booked from Oct 13-29/ 2018. Do I need to get a letter from him and what should it say. Thank you