First week of August We stayed at Jude travel park in New Orleans. Tight sites but we where there for the city. $40 a night. Fifteen minutes to French quarter. Great info on where to go and park cheap. Near Lafayette we stayed in carencro at bayou wilderness nice place and nice pool with slides for kids, under $35.
If your intent when in NOLA is to visit the city, I'd suggest Bayou Segnette State Park. Very nice campground, and inexpensive as well. Located on the south side of the Mississippi River directly across from the city, it's a great place to base camp. There is a ferry about 20 minutes away that takes you across the river to the intersection of the French Quarter and the Arts District. Cost is a buck or two each way and it runs every 30 minutes. Parking at the ferry terminal is $5 or $10 per day depending on weekday or weekend/holiday. Definitely where we'll stay again.
Fontainbleu State Park in Mandeville which is on Lake Ponchartriain or Fairview State park in Madisonville which is on the Tchefuncte River.. About 15 miles apart. Hour north of NOLA.
For NOLA, we stay at French Quarter RV. One of the most memorable meals we had was nearby at Louisiana Bistro . Also recommend stopping at Acme Oyster House for grilled oysters.
A second vote for Betty's in Abbeville. Be forewarned, it is a bit different. Betty essentially graveled over her smallish back/side yards to allow for RV parking. It's tight, and has no amenities except hookups. Forget about kid activities, or even dog parks (dogs are happily permitted, just that the "CG" is really small!). BUT - Betty also has an expansive covered patio, in which campers are almost required to attend the nightly "Happy Hour" - BYOB, and light snacks/appetizers. This is socializing, not a drinking party. Everyone chats about what they did during the day, places they found, where they ate, etc. Betty will very frequently host or organize tours and field trips to local events/attractions, based on the group discussion of the evening before. Or the campers may decide to have an impromptu crawfish boil the next night on site. Sometimes there's music, either by the campers themselves, or a local friend stops by. It's as close to being invited to stay at someone's house as you can get!
Don't delay because of the flood. We are recovering and most of the businesses are open in the Lafayette area. I haven't heard of any campgrounds being closed. The only exception would be Denham Springs, The whole city went under. There are plenty of good places to eat. like Prejeans, Fezzo's, Dwight's, Riverside Inn, Don's Downtown, Randall's. And that's just in Lafayette!! There's more in Breaux Bridge and Henderson, and New Iberia. Come on down and enjoy the food and culture.
When we went to Avery Island/Tabasco plant we stayed at palmetto island state park near Abbeville and loved it. Shuck's restaurant in Abbeville was fabulous. Don't what it's like now with all the bad weather and all.
Ponchitrain landing in New Orleans is great! Rough road getting in but once there is a bueatiful park. Pool, bar, restaurant . Shuttle three times a day into the French quarter. About a two and half hour drive to Avery island which is really cool. Stock up on Tabasco stuff there, it's cheap!
I think I would wait for another time when there are not so many communities under water. It's still raining and there is historic flooding in the state. They have declared an emergency for the entire state. Better check weather and road conditions for the area you want to go prior to leaving. Many roads are closed.