The exchange between Bishop John Howe (Central Florida) and the Archbishop of Canterbury gives some further insight.
“Any Diocese compliant with Windsor remains clearly in communion with Canterbury and the mainstream of the Communion, whatever may be the longer-term result for others in The Episcopal Church. The organ of union with the wider Church is the Bishop and the Diocese rather than the Provincial structure as such…. I should feel a great deal happier, I must say, if those who are most eloquent for a traditionalist view in the United States showed a fuller understanding of the need to regard the Bishop and the Diocese as the primary locus of ecclesial identity rather than the abstract reality of the “National Church.” - Abp Williams
Bishop Howe’s pastoral letter here
Archbishop of Canterbury reply here.