most accidents are repairable but it's down to the assessor. we've had cars that we started to strip down then the assessor told us he'd written it off, then on another occassion we had a bmw, not too disimiliar to your damage but also the rear was caved in due to a following car going into the back of it aswell, we didn't take a second look at it, then the assessor told us to repair it!!! you can never really tell when it comes to assessors
best way is to lift the carpet and take a look underneath, if the floor pan is creased then just the jig work will be £800+ alone let alone the rest