Some areas get very crowded, others aren't so bad. This will let up after the second weekend usually. By then most birds tend to start avoiding blinds and hang out in the center of the bigger bays. Most everyone hunts from a boat in the lower delta, the mud is too soft to walk in, so you would have to use a boat to retreive your birds unless you have a dog. If you do have a dog be careful for gators. I saw one last weekend that was 13-14 feet long.
Also, if you hunt from land in the delta, I believe you would need a WMA permit to hunt from wildlife management area land. You might want to check with a Game Warden on that.