I am travelling to Shanghai and Hong Kong in July and for accommodation looking for private rooms, not dorms.
Is it realistic to travel "freestyle" and book hostels when we get there or a day in advance online (when we know what train we're taking, etc.) or do Shanghai/HK hostels sell out in July?
update:
We booked our first hostel in advance, the rest of them while travelling, a few days in advance when we knew when we would arrive. We didn't have any trouble, though for Hong Kong, I wouldn't wait 'till the last minute.