In election year 2016, 538,410 absentee ballots were submitted in Virginia. Currently, in Virginia, 675,521 people already voted absentee in person, and another 531,910 have voted by mail for a total 1,207,331, as of October 16th. About 600K ballots have been mailed but not yet returned. As long as those ballots are postmarked by election day, November 3rd, they will be counted. More early voting stats here.
Reasons for this record early voting include fears of COVID-19 at the polls on election day (mostly Democrats), highly motivated voters (mostly Trump supporters), and the rules change this year that allows early voting and mail-in voting without any excuse. (You don’t have to claim to be on vacation election day or have a very long commute, or your mom may be sick.)