In an email to current ticket holders last night Mid Ohio Sports Car Course said that the Honda Indy 200 on the weekend of August 8 and 9 will allow a limited number of fans to attend the race.
As of this morning tickets are still on sale. I ordered tickets for Sunday only but it appeared all categories of tickets- weekend, Saturday, and Sunday- are all available on the website.
The track did not say what the cutoff number is. Like Road America, there is room at Mid Ohio to spread out the crowd. The Honda Indy 200 is the last race before the I 104th running of the Indianapolis 500.