You could always settle in the Mojave, plant a grove of bristlecone pines instead.

I don't know if more boreal climates support longevity, I think it has to be some combination of temperate + dry + safe from natural disasters like wildfires and hurricanes

Even for other kinds of long-lived trees, places without big ice storms, hurricanes, etc. that would prematurely end the tree are probably safer bets.