I have gone that way to avoid DC but depending on the time of day, going through Gainsville and Leesburg can be slow.
Note, where 15 leaves 29 in Gainsville, it is a left turn onto 15 north, you will need to be in the left lane. Once you leave Gainsville, it is mostly a two lane road up to Leesburg. Pretty drive though through the rolling hills of Virginia.
HTT: "EscapeII" 2016 Shamrock 23WS (current)
PUP: "Escape" 2010 Rockwood HW 277 (gone)
TV: "Bruce" 2011 Dodge Durango V8 Hemi Crew
Just us gals (me, Sis and our daughters)
Traveled 19520 miles and 209 nights in 7 years and counting