I'm thinking you might want to up your temp, cooking at 225, it's gonna be a long, long, long time. I'm also thinking its probably two 12.5 ish lb briskets.
Wow, that is big!:shock: If it's not completely thawed after 5 days, it should be mostly thawed and you can put it on. I would bump up the temp too to the 275-300 range.