I live in Ohio.
In most circumstances, you can not appeal the denial of a change of venue motion until the entire case is concluded in the trial court.
Under Ohio law, only "final appealable orders" can be appealed. A final appealable order is one that completely disposes of the case. But in the situation where the trial court denied a change of venue motion, the trial court is not disposing of the case, and in fact, the court intends to proceed as per the case management order, unless otherwise stated.