We prefer to have me, my wife and two kids, 12 and 15 in one room. Will we fit?

I think it is too crowded to accommodate your family in one room. In China, each room can only add one extra bed with 0.9m wide. And the hotel bed's size is small and it is hard to for three persons staying in one bed with 1.8m wide. You should stay in one suite or two connecting rooms.