Can we share one room if bedding accommodates 4 adults.

I'm afraid that it will be crowded to accommodate four adults in one room. There are mainly two types of rooms in hotels in China. One is double room with one large bed, the bed size is around 1.8m X 2m. The other is twin room with two single beds, each bed's size is around 1.1-1.3m X 2m which varies in different hotels. So I suggest you stay in two rooms.