My family of 4 (with 2 teenage boys) is considering a 2 week silk road trip in early Dec 09, starting from Urumqi/Turpan to Dunhuang, Jiayuguan to Xiahe & Xian. Is this period suitable for sightseeing at places like at heavenly lake, sand dunes sliding/camel ride, magao grottos, jiayuguan, grasslands at Sangke? What's the temperature like and is sand storm common during this period? thanks.