Solid engine, will be paired with 8-speed Tiptronic. If this has mild hybrid 48v they can be a nightmare to repair. 3.0TDI has lots of low end torque.
Diesels don’t like town driving, so if mainly country driving and motorways, that’s fine.
You’ll also find these Euro 6 diesels have DPF, EGR, AdBlue, etc. That’s fine as long as engine gets to temperature and decent runs 30 mins or more. I add Forte anti-crystal to every AdBlue top up and run premium diesel only. Fuel filter needs changed every 20k miles. I also change oil every 5-6k miles. I’m spanner handy, but this will be my last diesel, so I don’t want any crippling bills.
If you’re buying with Audi finance you can usually get 2 year warranty, or 12 months if cash only. Maybe Audi have changed their sale proposition, but that’s my experience.
If the car has only had 2 oil changes in its life, not unusual on long service intervals of 15-18k miles, I’d look elsewhere to be honest, irrespective of the mileage.