I have a friend who commutes from Arlington, down the WO&D and across the Key Bridge into DC.
I’ve also taken the Mount Vernon Trail and crossed the Theodor Roosevelt Bridge and entered DC by the Kennedy Center.
DC has made some very good improvements on the surface streets, adding protected bike lanes
On the weekends, early, it’s pretty easy to ride in DC. We did a ride to hit the streets that are named after the first 13 colonies, it was surprisingly chill. I’ve also lived in DC (first job out of college) and used a bike as my main transportation in combo with the buses and metro and IMHO, it wasn’t that bad.
Weather wise, I have a friend who commutes by bike further out in Northern VA on the WO&D through the winter. It may get somewhat chilly but we don’t get all that much snow. With the right base layer, jacket, and some barmitts, you should be good to go. I did Freezing Saddles this year and managed about 500 miles outdoors since January (which is pretty good for me since I’m not a fan of the cold), but the top riders in the competition had something like 2000-3000 miles riding over the winter.
The swamp heat of summer with high humidity and high temperatures are another story, as you will need that shower at work.
FWIW - If you lived in Falls Church, which is roughly 10 miles from DC, you’re still 20 miles out from Dulles Airport. If you lived in Rockville, Maryland - that trip to Dulles airport is 30 miles (though you would have to come around the beltway) - Just saying Being close to Dulles is relative since it’s pretty far west of the City.
Some Good Resources: