Yes. Balance reduces to max cashout the moment you finish wager. If you are on autospin be careful because it will keep on spinning.
I have managed more than 10 cashouts from no deposit free spins at Iwild and snatch that's how I know.
The contest has not started yet. If you play today your history will show todays date which is 20th. You can start playing after your clock hits midnight.
These contests will happen throughout the year so you will get a chance in future. Contribute to the forum. Create some gambling related topics and make forum posts in the mean time.