I’m in Vegas (which gave me 4 inches of snow last week) so I know of which I speak. We have very similar climates normally and very similar species of flora and fawna.
Don’t water. Anything which is wet will freeze. Anything which freezes will die. Moisture is your enemy. Do not water until the freezing it over.
You want to cover any landscaping or irrigation pipes which are above ground. That is your most likely victim of freezing. The water in the pipes will freeze, shrink and pull the gaskets out which causes non-stop overflowing (which could then freeze if it stays cold long enough). Trust me, I’ve seen people with four inches of ice covering their ENTIRE YARD in Las Vegas because their irrigation pipes broke and flooded their yard which then froze into an icerink. You DO NOT want water on the ground or on any plant.
If you have delicate plants, those you can cover. Growers down south in Marana used burlap in the past but now have been synthetic fabrics which are cheaper. Freezing kills fruit. Anything which you need to bear fruit and is in the process of doing so will drop its fruit.
Palm trees, no problem. Mesquite, no problem. Palo Verde, no problem. Most trees, no problem. Leaves will die and fall off but one single freeze won’t do any long term damage.
You need to protect your water lines more than your plants. I spent lots and lots of time just south of your current position and I weathered lots of below freezing winters in the mountains. Nothing overly special was ever needed. Plants take the cold better than people do.
Just make sure you don’t have animals outside who aren’t covered, sheltered well.
“Anything which is wet will freeze. Anything which freezes will die. “
Baloney. The ice acts as an insulator that keeps the temperature near 32 deg. Ice is used all throughout the south to insulate fruit crops.