Can you really see DC (or other northeastern cities or CA) opening to more than say one quarter capacity? A vaccine will at best be like 50 percent effective. Most older people are still going to avoid big crowds.
by 2021 i believe we will simply be operating with a new normal. elderly, high risk have to be more careful, the rest of us try to live safely and smartly. maybe we have treatments, cures, vaccine.
baseball absolutely cannot afford a season with no fans. team budgets will plummet next year and empty stadiums again would be a death sentence.