In the quest for vibrant, affordable neighborhoods, some Bay Area professionals are moving north—way north, to Portland and Seattle.

Scott McNeely is a transplant to the Pacific Northwest who kept his job in the Bay Area. Mr. McNeely, online director for San Francisco-based Internet travel company Viator Inc., used to live in the Mission District. But several years ago, he and his wife began pining for more kid-friendly environs after becoming parents.

High...