"The Undying/The Immortal" and raid extensions...

Does anybody know if "The Undying" and "The Immortal" achievements can be obtained through a raid that is extended past one lockout period with the new raid ID extension feature?

I'm curious, because the way my raid guild works is we run Naxx until our full roster is logged on, then we head to Ulduar once we have 10 online. Normally, this would mean all we see of Naxx in a week is the earlier bosses, but now with the raid extension feature we can extend Naxx out to farm the later bosses.

Last night we downed 5 bosses in Naxx with zero player deaths and we're extending it into this week as many people (or their alts) still need gear from the later bosses. I'm wondering if we'll be able to earn the achievement if we manage all fifteen bosses with zero deaths...

The achievement text reads "within one raid lockout period...", but that was implemented before the raid ID extension feature, so I'm wondering if the achievement is earnable "within one raid ID" now as opposed to "within one week"...

99% sure it's tied to the raid ID.