Baja California is safe except for the city of Tijuana. You just drive across the border but you need a passport to get back into the U.S. Use ONLY premium gas. We have driven all the way down to La Paz and back as well as San Felipe several times and Ensenada a couple of times. Some years ago I drove to Mexico City and back but I probably would not do that today.
But to answer you, Hwy 5 from Mexicali to San Felipe and with your tow car on to Puertecitos is a great trip. With your tow car you might drive 20 miles beyond Puertecitos. We drove a Class C 85 miles beyond until the dirt road reconnected to Hwy 1 that goes on to La Paz. San Felipe has lots of MH parks. Go on the internet and get to book "The Magnificent Peninsula" by Jack Williams. It has Hwy maps, city maps, and detailed explanations of all the sights. There are also many other books.
I think the 7th edition is the latest and I saw prices that were out of sight for the 7th edition. We have the fifth edition and it is GREAT.
When driving in Mexico the best thing to do is make sure your current US insurance will cover your vehicles for collision damage and only buy Mexican liability and property damage insurance WITH Mexcan legal representation included. This is because Mexican collision coverage says that your vehicle MUST by repaired in Mexico. On the other hand, usually Amerian collision coverage, that includes Mexico, says that it will pay for repairs to enable you to drive out of Mexico and have the repairs done in th U.S. If your vehicle needed to be towed out of Baja you would have to ask about that.
JerryF