canonical,
Protestantism is the refusal to recognize the Church of the Fathers and to acknowledge that the Holy Spirit illumines and guides the Church. It is the introduction of innovation and new “theology”, yet their loose “communion” remains intact. And despite their different and varying “theology”, they all consider themselves part of the same warm and fuzzy church.
This describes the new-calendarists, not the traditional Orthodox Christians.
When the Orthodox speak of the Orthodox Catholic Church, they do not mean only her bishops or the contemporary Orthodox Church throughout the world. The Catholic Church is not only the Church militant, but the Church triumphant as well. When any members of the contemporary “official” "Orthodox" Church throughout the world act in opposition to the triumphant Church of the Fathers, then those individuals who rise up against them in order to remain in communion of Faith with the Church of the Apostles and Fathers are not “Protestants”; on the contrary, they are the only members of the Church militant. They do not perpetrate schism by not following the contemporary hierarchs who tread their own individual Protestant paths; rather, they constitute the Church, because they alone are one body with the Apostolic, Catholic Church of Christ.
And odd how the Protestants of every denomination applauded the Ecumenical Patriarchate and all those of the WCC ever since they preened themselves with the encyclical of 1920 which proves them to have been the pioneer in the Ecumenical Movement and “orthodox Protestantism”
So to answer your question, how do I draw the line? The line has already been drawn by the fathers. Whoever 1) is in communion of those who hold the true faith, 2) who have apostolic succession stemming from predessors who also held the true faith, and 3) were not formed for reasons other than heresy or communion with heresy. Of course not everything is black and white at first, but time often reveals everything.