Lake Havasu was too hot for us, so we went to the Mojave Desert.  Really.  It was much cooler in the Mojave due to being farther north and, I think, a higher elevation.

This spot was one of my favorites.  We were by ourselves a good distance from the highway.  There was a town 30 minutes away and we had excellent cell phone data reception.  I think that this might be a place to spend an extended amount of time in the winter.