The Marlins can relocate at any time. By breeching the agreement they will be responsible for damages which will either be negotiated or come in the form of a suit and a determination of damages from a judge. If a new venue with new projected profits significantly exceeds the damages, say around 2040, it may be in their best interest to just write a check and walk away! It's sad because the venue is fantastic. I was there in late August. I don't understand why the team doesn't do better at the gate.