Betty, several things. 1. Older cars can be worked on by old style mechanics who do not have computers to tell them what is wrong. That makes it easier to get back running on weekends or in small towns without a dealer. Ranch mechanics can do anything. 2. You can pack things in your car so a breakdown is an inconvenience, not an emergency: food and lots of water, travel pillow, blanket or sleeping bag, polymer female urinal, etc. It depends, but generally it is safest to stay in your car with seatbelt on. 3. Be aware of where you are so (if you have cell service) you can tell the operator exactly where you are. Make a game of remembering mileposts and street names in unfamiliar territory. Do not depend on a gps (even satellite ones) to tell you where you are.
That's the practical stuff. An additional consideration is, your car will at some point break down no matter what you do. You take care of it in hopes of postponing the breakdown until after you replace it. But really, it is more convenient to break down on a trip when you have extra time to deal with it; much less stressful than when you have a trunk full of groceries needing to be kept cool, or you are on your way to an important appointment. The attitude adjustment is the bigger deal (and can also be used on loved ones who think you should stay home, "act your age" and behave).