Personally, I don't think you should put it off, but the choice is ultimately up to you. I just "wonder" what will be the "next" excuse . . .
Now you know yourself better than anyone else, and if you go to Mardi Gras and smoke, well, you know, try again the next day. But I don't think you should put it off.
What if you do quit smoking and DON'T smoke at Mardi Gras . . . you're on easy street then . . . right? If you can make it through Mardi Gras w/o smoking you know you've got it whipped, if you do "slip up", oh well, try, try again . . . right.
Good Luck to you, either way you go. We're all here for ya'!