We are renting a Westfalia in LA, starting December 14. Our plan is to go down Highway 1 to San Diego but besides beach side towns we are interested in the desert and National/State parks like Anza Borrego, Joshua Tree, Death Valley, Palm Springs.
The problem is that I'm having a hard time deciding about an itinerary because I don't know exactly above what elevation we shouldn't go, weather wise.
We are escaping our hometown snow/icy roads/bad weather this year and we wouldn't like to freeze overnight in our little Westfalia.
Could you point out places that are likely to drop around freezing point overnight and places where it could snow in the places mentioned before?
I'm looking at National Forest/BLM web sites to find either free or inexpensive campgrounds but it's a gigantic task to try to go through all the information that is available over the net...
Of course I presume that a campground situated at 7000 feet can get snow over Christmas but is there a general rule of thumb to help me plan our route?
Thanks many times,