Really sorry to see this. Rubbish luck.
Insist on a full quote for the repair, including labour, and a damage assessment that includes some definitive wording re. the nature of the structural damage (i.e. door crash structure and panels only and not inner sill, chassis etc). The former you can get from your insurer, but the latter you might need to nudge the engineer about when they look at it.
Then at least if they can't repair it economically back to an "as new" state, you have proof that you can do so yourself to a "roadworthy" state in the event that you decide to buy it back as scrap. And buy back prices seem to be as alarmingly low as valuations!