Thanks everyone for the input. I think we are going to give this a try, likely with an overnight layover on the way down in MEX. The plan would be to stay at the NH hotel in T2 and catch the 10am flight down to SCL the next morning.

We are pretty invested in AS which is why LATAM has some appeal to us, although maybe this gives us a chance to try out DL from SEA instead. The AM fare is just so much lower than what the competition is offering.