Gumbo is fun and great tasting. Making Gumbo at home and making it at a tailgate in the parking lot are two greatly different things.
First of all the essense of gumbo is the roux. If you can make a great roux standing in a parking lot, possibly under rain or cold conditions, then you should have no problem. If you use "fake" roux, as in frozen or pre-made, or heaven forbid- packaged- then the rest of the ingredients should make no difference whatsoever. Just have lots of beer and no one will notice.
If you want to make good gumbo in either the kitchen or the parking lot- read K-Paul's book, Louisiana Cooking...
Favorite Quote: "Time Flies Like an Arrow - Fruit Flies Like a Banana"