I think I get it. Well, a couple of thoughts...
- as I noted before, if you're booking right at 6am on day 180, I'd try for a party of 2 before ever trying out this whole 2 different ADRs for a party of 1 idea. i.e. better to try for something more ideal before having to get too creative.
- my 2nd thought...if you have to resort to trying for two separate ADRs for a party of 1...do you have 2 separate Disney profiles/accounts? You'll need it because the system will view it as a double booking and force you to cancel the other.
While I've never used any of them, there are some sites out there that are paid services for ADRs. I guess they are set to automatically send you an alert when the ressie you're trying to get has an ADR opening. Just thinking it might be a good back up plan if you need it.
Either way- wish you the best of luck on getting this booked 
