To answer my own question, I did a google search. While I don't follow him at all, this came up at the top of the hit list:
Code:
https://thepointsguy.com/2017/11/how-far-in-advance-book-airfare/
Alaska: "If you’re looking to book an award ticket on one of Alaska Airlines’ partners, you can book up to 365 days in advance, pending the partner’s booking rules. Use the chart below to tell if you can book further out." (included chart shows CX bookable 360 days out).
American: " you can book up to 331 days in advance of the departure date, regardless of when partners open up their flight availability."
So. While I have way too many American miles, I also have enough to book the 3 flights I need (including 2 different home options, 1 to be canceled later) using Alaska. And that also gives me the chance to stop over in HKG and then get to REP on the same outgoing award (thanks everyone for the suggestions!).
I'll gather my facts and details and call into Alaska Airlines tomorrow. I do have to still book a positioning flight to Chicago, and I'll use my ample AA miles for that
. Ditto coming home.
UPDATE: I started to collect my desired flight information this morning, only to realize that if I am trying to "stop over" in HKG and continue on to REP ~5 days later, I have to wait for the REP flights to appear on the schedule. So I am still ~2 days off before I can book. At the same time, I'm still considering a wait-gamble so as to use AA miles for this. Perhaps I can't do the stopover, but I can do HKG->REP using 7.5k BA Avios each, and I've got lots of those too.