Thanks for the responses.
We need two J seats, so looks like this won't work.
Super frustrating to have every miles and points blogger on the interwebs saying "Wow. Alaska Airlines miles are THE BEST! You can book a one way from North America to South America on LATAM for only 45k Alaska miles. WHAT A STEAL!"
What are these bloggers smoking? You can also win billions of dollars playing the PowerBall, but the odds of actually winning are slim (But maybe higher than finding 2 J seats on LATAM with Alaska miles lol)