Not sure what your budget is so I’ll just cover all the things

Those 5hr Hand warmers. Windshield scraper 2 buckets, 1 labeled margarita salt the other driver way salt Warm socks Chap stick A blanket for the car (just in case) An outside thermometer that goes to -40f, but mark it where the usual AZ min is in winter Snow tires Snow pants Snow boots Snow shoes Ski pass Skis