Joe raises a good point about getting around the Seattle metro area. For those not paying close attention, a major highway through the city will be closed for weeks (actually they're tearing it down), starting January 11, and the replacement won't open for a while - projected opening is around February 4th or so, but with any project around here things rarely happen on time.
What is nearly certain is that with this highway unusable, the entire region will immediately go to complete gridlock, with travel times between most points going off the scale. Anyone planning to casually get from one place to another during this outage is in for a shock.
I expect that the city will grind to a complete halt, with people stuck in their homes, unable to get to work or anyplace else, with commerce and almost all movement essentially freezing. I have to get to the airport for a flight during this time, and I'm planning to go in the middle of the night and allow 4+ hours to get there (without traffic the drive takes just about 20 minutes).
It's going to take weeks (maybe months) for the transportation system to start loosening up a bit (my fear is that free movement around the region will never return, and this is actually by design, but maybe that's just my low expectations about the charlatans and religious zealots that rule over the city).
Bottom line: don't count on being able to get around this region very well for an extended period from early January until sometime in February (at the very earliest and most optimistic). Stock up on supplies and anything you might need to survive for a couple months before the roadpocalypse starts around January 11. Good luck.