An excellent question. As far as the strategy of the game goes, it's likely to change somewhat, because a team is looking to attack another team's weaknesses, so the actual X's and O's is impacted very little. Where the change is likely to be is the mental part of the game, not having fans in the stands, the lack of crowd noise. These athletes have NEVER played in empty stadiums as long as they've ever played the game, so it has to impact them in some way I would imagine.
It's definitely unprecedented, so I'm sure you're going to see varying opinions on this, and who knows how the game will be when it starts back up again.