One encounter a day isn't realistic; you typically have 4-5 CR equal encounters.
The Wizard can do it over and over again because it's free; UMD characters, not so much.
As a more general comment, I would like to say that I built Carry the Commoner with the intention of fighting a single monster (a Pit Fiend) in an arena battle.
Most arena fights I've seen forbid surprise rounds and teleporting out of the battlefield. That's why I didn't plan for them.