You can freeze mac and cheese — but I prefer to make smaller batches of this macaroni and cheese and refrigerate leftovers since they tend to reheat better than frozen. To freeze leftover macaroni in cheese, it's best to divide leftovers into smaller portions rather than one large block. Freeze in airtight food storage containers or freezer bags, removing as much air as possible to minimize freezer burn. To reheat, defrost overnight in the refrigerator and reheat on the stove or in the microwave as noted above.