I suggest that you get a second chase card and fly in F to BKK on CX. Only 150K per person return and $250 or so in tax.

Alternatively you can buy 24.000 extra miles, make one or two actual flights on AA before then and fly F out/J in or vice versa. December is the best season for Thailand, so book asap. I assume you travel alone for the 100K miles. If not, you need to trigger a 241 asap. Not sure how that works in the US.

Flying through LHR on BA will up the ante considerably.