I read Patriots, and liked it ok, but didn't think it was one of the best post-apocalyptic books I'd ever read. Anyway, after TSHTF I wouldn't say "there won't be ANY law." I'd say the only law there is is what you(or your group) can enforce. Some areas will have a lot of law, and other areas will probably have none, but the main law will probably be the "law of the jungle".
I'm your huckleberry.