On my ONE5, I was given a 21-day hold deadline by the AA RTW desk, but when I called to have it extended, it was no problem at all (no questions asked whatsoever and didn't need to involve a supervisor, luckily). My original hold deadline was 27-Nov and my new "deadline" is 27-Dec, but I'm guessing I could get that extended again.

The only caveat is they said that my fare would have to be re-calculated after the original hold date (27-Nov). So, I guess the only risk is that the fare will go up the longer I keep holding it. Of course, I guess there is also the risk of rules changing (?).