When I had that commute I would buy boxes of clifbars and power bars that permanently populated my glovebox. Trail mix in Adams peanut butter jars. Flavored oatmeal with raisins in old jam jars, just grab a cup of boiling water on your way out and pour it in. See also, instant mash potatoes, stuffing, ramen (adding boiling water to ramen and just waiting for it to be ready is the only way I like it now). That was the best idea I ever had before a multi day road trip, please use it.
If anyone has ideas to add to that, I'm all ears. Or any other food-from-home non-shopping ideas (like eating potato salad with Tims salt and vinegar chips, bombdotcom)
Order the meat without salt too. They all season on the flattop so it'll force them to make fresh.