Lots of different info out there on this, but around 100K Jewish population in PHX / Scottsdale (I've heard even more, actually), around 100K in Denver / Boulder. Another 150K between DFW, Austin and Houston, 60K in St. Louis, 50K in Mexico City, we're almost to 500K now. Just within a 2ish hour flight range of DFW.
Add in connections from GRU, EZE, and we're getting closer to 1M.