Q.tomato plants freezing
I live in the high desert in California. I have several tomato plants that have tons of green tomatoes on them. I am trying to save them from the horrible frost temperatures, now down to 18-28 degrees. I have done okay for now and have gotten a few to ripen but I am concerned with the other 60 or so tomatoes. What can I do to save them besides double frost blankets? How about a visqueen enclosure or what? Need an emergency solution. Also, how long before they finally come to fruition? Cutting off dead black branches as needed. Plants under are still looking good and green.

You can likely extend the growing season for a few days or longer by covering in the cold temps, but tomatoes need warm weather to grow and will began to die back in the cold.
I would harvest the tomatoes and continue to ripen them indoors.
Here are some links to help you.
https://www.gardeningknowhow.com/edible/vegetables/tomato/growing-indoor-tomatoes.htm
https://www.gardeningknowhow.com/edible/vegetables/tomato/how-to-turn-green-tomatoes-red-how-to-store-tomatoes-in-the-fall.htm