Generally, I believe, it's been "leave the silverware at the door." There have been specific cases in specific locales which had had laws that block that, allowing the departing parish to keep the property, but the general issue of who really owns the property (the Dennis Canon) has not been litigated.
If they affiliate elsewhere in the worldwide Anglican Communion they can say they're not part of ECUSA, they're not supporting Griswold & co with their money -- but they're still in communion with ECUSA!
For all I keep explaining why things take forever in the Anglican world, even to me the split is long overdue.
Thanks for your explanations. They certainly helped me.