Minimal chance of rain or freezing weather. If they stay on I-10, which is the only logical way to go, they should be fine. Do what I did with my parents...insist that they get (and keep) a cell phone. AT T has roadside assistance available for about $3.00 per month. Peace of mind...priceless!
Should be OK. Like Donna stated stay on IH 10. Tell them to stop often. Overnight also. The motel can look up road conditions if they don t have a laptop computer.When I drove to Las Vegas last year, I bought two cell phones from different companies, I didn t have problems talking in West Texas. We belong to AAA also. The Weather Channel /weather.com and NOAA /noaa.gov are helpful.