It's a Volkswagen w/ a tried and proven engine, it will last forever
*IF you are willing to pay for maintenance and repairs.
As you have a Sportwagen TDI, I assume you are familiar with VW maintenance needs. Also realize that you will be looking at low 20s for MPG with AWD and mid 20s with FWD. What it needs in the next 50k miles kind of depends upon what has been done. Inside of 150k you WILL need to replace the cam timing chain in my experience no matter the year. The '13+s have the better chain tensioner, but the chains do wear/stretch, especially if it was on the 10k oil change schedule. The PCV assemblies are maintenance items. The water pumps are fairly high failure items. You will also have at least one major tune up with plugs, filters, etc. Then there are common oil leaks, like front covers and vacuum pumps. Those need to be taken care of as they arise so they don't lead to bigger issues. The good news is that the transmission is rock solid (Japanese AISIN brand), and the bodies and interiors hold up really well, usually making up for mechanical issues, IMO.
My daughter is a junior in college 500 miles away from me and has been driving an '09 Tiguan since she started driving. Not the same one, as one got totaled (seems like every 16 YO totals a car...), but I fixed it and it is now perfect again and I drive it. She now has a loaded '09 SEL (what was my daily) that I got with a jumped chain and repaired. On that one I rebuilt the head, replaced the intake manifold, water pump, PCV assembly, resealed the vacuum pump, gave it a full tune up, etc. at around 92k. I see it now two or three times a year and do whatever it needs for service. It will be back in a week or so for tires, a windshield, and maybe brakes. The plan is for it to last until she is out of college and can get her own car. So far, so good, but I have no illusions that is will be without problems. It is still a VW, and I already have a VW specialist shop picked out with their number in my phone in her college town if something happens that can't wait. Right now it is just a really nice, safe, AWD vehicle that I have not much into that I know like the back of my hand (because I need to). I have less into it than I would lose driving a new vehicle off the showroom floor.
For my non "car guy" friends, I tell them to get their kids Toyotas, like a Corolla or RAV4 if they need AWD. It will be bland, and you will pay more, but it will stand up to lots of neglect and always start. If all your kid can put into their car is gas and friends, then that is the vehicle for you.
YMMV
