No major retailer sells frozen Mexican cornbread, nor do they sell standard frozen cornbread. However, various Mexican-style cornbread mixes may be purchased, and mostly, any grocery store offers preprepared cornbread, which can be frozen and later thawed with no significant harm done to the flavor.
Although frozen cornbread can't specifically be purchased, there are many other breads that can be bought frozen, including garlic bread, cinnamon bread, bread sticks and basic bread dough. It is important to note that most types of bread are left completely unharmed if bought already prepared or manually baked by the consumer and then frozen for later use. For the best results when freezing bread, do not wrap warm or fresh bread, wait until it has cooled down to avoid sogginess and mold. Then wrap the bread in plastic wrap or place it into two or more plastic bags (or a combination of both). In order to thaw the bread, simply let it sit in the refrigerator overnight.
Note that storing bread in the refrigerator for long periods of time offers no real benefit and just makes the bread hard and unappetizing. If attempting to store bread for long periods of time, stick to freezing it.