Well done on signing up for a half marathon. I ran a 10k last year and would love to do a half marathon, think i will do another 10k this year and try half next year.
I would agree with you though, extra easy plan would be a good plan to use as you are getting a mix of your carbs and protein, maybe add a couple of green days a couple of days before the race itself but even then i would think extra easy would work just as well as you would stillbe having your carbs - a nice big spag bol, yummy.
Good luck.
Caroline