DL has NYC-SJD (Cabo San Lucas) on sale for $370 with scattered days in the fall/winter/spring. Sample dates 9/22-9/24, no holidays available. Can route it EWR-DTW-MEX-SJD with the MEX-SJD legs on AeroMexico, which will still earn full MQM on DL. Can book on the DL site. Earns 6,096 MQM, for 6.1 cpm. Not great, of course, but not bad for a warm destination in winter.