First of all if UCITA is passed, what you want just might be legal. Needless to say, few of us think much of UCITA. But beyond that if you or your partner have brains you will have a backup strategy in place. While a good backup strategy would make what you want much harder, it would also protect you from all sorts of disasters that could happen. (Such as a computer crash.)

Beyond that I would recommend making a copy of the whole site for your own use, and talking to a lawyer. Which is advice you have heard before...