In the United States, it typically takes 11-12 years to become an M.D. without specialization. This includes 4 years of undergraduate studies, 4 years of medical school, and 3-4 years of residency training.
Most of the state and interstate roads are well plowed, maintained and patrolled so, if you are staying on the beaten path, you should only need a two or three days of emergency rations. By then, the state police should be able to find you. If you are heading into the wild and want to prepare for worst case, calculate 1 pound of high-energy food per day, per person. For walking out of the wild, an average hiker can travel 7-10 miles a day in the snow. Therefore, absolute worst case, assume 50 miles/7 days, so you would need a total of 7 pounds of foods per person. What you bring should depend on a few different variables. How many people are going on this car trip and what season is it? At a minimm you should bring 4 days worth of water (approx. 4 Gallons) also, easy to prepare meals should be brought. Granola bars, Sandwich ingredients and individually wrapped snacks are quick and easy. MRE's are small, lighweight and very good tasting and filling