Hello,
If I may offer any help, here goes.
I host in Rio and I got great prices during the Olympics 2016.
I charged the nightly rate during the Olympics equally to the nightly rate of major events that takes place in my City, such as Carnival feast.
If I were you, I would block the dates of the games for a while to prevent that some guest book it at once for a low rate. When you take a decision then you set the dates available again.
I suggest setting a minimum stay during the games (such as 7 days) to prevent booking for just few nights.