Do people with experience think it is reasonable to catch an early train from Ollantaytambo to Aguas Calientes , tour Machu Picchu for the day, and return to Ollantaytambo the same evening? Or is it better to stay in one of the Aguas Calientes hotels the night before? Can you do the Huayna Picchu hike during rainy seasion? Are other Sacred Valley activites, such as mountain biking, horse riding, and rafting happening during rainy season? We will be there in March 2009.