Preservatives are found in processed foods, not vegetables. Organic vegetables generally don't last any less long than normal ones.
They make lots of organic frozen prepared foods. You can get organic macaroni and cheese in a box that's just like the regular (but tastes better). There are organic canned soups, pasta sauce, frozen burritos, etc.
Be careful with this. You can get the "USDA Organic" logo with less than 100% organic ingredients. So it's possible that your frozen dinner has preservatives and other crap in it that you are trying to avoid by "going organic". Read the ingredients to be sure. If it's something you can't buy and add to your food yourself, it's probably in there for the seller's benefit; not for yours. (Less spoilage == higher profit margin.)
They make lots of organic frozen prepared foods. You can get organic macaroni and cheese in a box that's just like the regular (but tastes better). There are organic canned soups, pasta sauce, frozen burritos, etc.
You name it you can buy it.