I've taken some pics. I hope they're helpful in your judgement.
I fear the car is more or less a goner...
The rear subframe looks to be intact with no signs of rusting....so you can drive the car into the ground at this point.
As far as making it look better to pass inspection...first use a rust converter to slow down the rust, then I'd use a can of expanding foam from Home Depot or the like and fill in the hole, shape the foam once it's cured and then body filler or fiberglass over it and paint it to match.