Ministers in the Church of England need to decide: will they continue to find reasons to be part of a "church" which blesses that which God says is grossly offensive to him? Or will they testify faithfully to Jesus, joining those "outside the camp"?
If this isn't a "line in the sand" for you, then nothing ever will be.
My personal viewpoint is that the real "line in the sand" - the fact that it is not possible for any minister of the Church of England to be disciplined for teaching a false gospel - was crossed many decades ago. That issue would be a line in the sand for deciding that I could not, in good conscience, be part of the ministry of such a church. If a church does not stand for the gospel, then it cannot be recognised as a church in good standing before the Lord Jesus Christ.
But, if you've let that pass, then here's the question: if you can tolerate false gospels and the blessing of what God says is absolute depravity, then what would you not tolerate? There's not much left, is there? Does the Archbishop of Canterbury have to personally sacrifice your firstborn child to Molech before you say "enough's enough"?
At the point that the Church of England's hierarchy is declaring that sodomy can be blessed, and you're still part of such an organisation, surely your only real line in the sand is "I can live with anything whatsoever in the wider Church of England - however false to God's truth, and however contrary to the order of God's creation or his law - as long as I personally am left in peace". Is it not so?