I'm also Bay Area based and confronting the challenge of how to find time to travel as part of a dual-professional family. Many of my trips end up being weekend and three-day weekend type trips. For these I look to the many places that WN serves via nonstop from SJC, SFO, and occasionally OAK. That's the first tip-- check all three airports to find a nonstop at a time that works for you. I'll choose a nonstop via OAK even though it's ~30 mins extra ground travel vs. taking a connection to/from SJC.

Your picks of LAS, MDW, and PDX are all good choices. Definitely look at SEA, PHX, TUS, and all of SoCal: LAX, BUR, ONT, SNA, SAN, and now LGB. Each of these are convenient to different parts of the Southland.