I made it to the airport, and it looks like my flight is on time.
I had to negotiate two blocks of bumpy, snowy sidewalk to the bus stop with my roller bags, but it was not too bad. It was easy from there: bus to the Capitol Hill train station, and train to the airport.
Now it’s 7½ hours to Reykjavik on Iceland Air, and another 3 to Amsterdam, where I will overnight on the way to Cape Town, South Africa.