What's ironic is that the marriage covenant is intended to show the permanency of God's covenant with his elect, whereas, you are attempting to show that God's covenant has an escape in it which justifies breaking the marriage covenant.
I'm just saying.
God's covenant with His elect is unbreakable because of the originator of the covenant. God establishes His covenant with His elect. The covenant is enduring and unbreakable because God is enduring and unbreakable.
The marriage covenant is a type of God's covenant with His elect, but this covenant is made between two imperfect people. The intent of the marriage covenant is one man and one woman for life. The imperfection of this covenant, because of human sin, only serves to underscore the superiority of God's covenant with His elect.
So, am I trying to show that God's covenant has an escape? No. Moses and our Lord did not state that marriage has any escape. Marriage is intended to last for a lifetime.