If the old were truly 'do or die' (instead of a covenant given by a God who IS love and full of grace and mercy) then Israel wouldn't exist. It says it right there in the Jeremiah passage you've quoted many times:
It will not be like the covenant
I made with their ancestorsy
when I took them by the hand
to lead them out of Egypt,
because they broke my covenant,
though I was a husband to them... Je 31:32
They ALL broke that covenant, the 10 commandments, written with letters engraved on stone, yet we see evidence that God did not 'do or die' them, because they didn't 'do' and they did not 'die.' No, instead, God showed grace and had mercy and was longsuffering with them and patient. He corrected them and gave them chance after chance after chance. They wandered in the wilderness when they should have died. They NEVER learned though! For example, show me ONCE where they EVER celebrated the year of Jubilee, the ULTIMATE Sabbath in the cycle of Sabbaths. There is NO record of it in scripture. But they did not die despite their continual disobedience. God was a husband to them, but they were a harlot in response.
We CANNOT be justified or made righteous by law-keeping. Jesus satisfied the requirements of the law in order that we could be justified and made righteous by faith in what HE already accomplished, not to send us back to what brought a death sentence in the first place, but to bring us to HIM. The theology you have bought into is an attempt to join death and life together in a spiritually adulterous relationship.
In Christ alone...