Upvote:5
The A320 has a maximum cabin width of 3.7 meters and cabin length of 27.5 meters, so with a requirement of 2 meters between passengers, that means 2 passengers per row, and an average of 13 populated rows, so ... 26 passengers.
The layout above would consist of two passengers in window seats on the populated rows.
If you want to juggle it around a bit more, you might be able to fit an additional passenger in the unpopulated row and meet the 2 meter exclusion zone, which would give you an additional 13 passengers.