By "minor off road" do you mean unpaved roads, or actually off the road? Something the 325ix couldn't handle, or only a similar level of capability?
An Acura MDX might be the best fit.
The Volvo XC90 has a third-row seat, but is a very old design with iffy reliability.
If you want a low-range and a luxury brand isn't a must, maybe a Ford Explorer or Nissan Pathfinder. Reliability on either is so-so (but less likely to be a horror story than the Volvo), and neither handles anything like a BMW.
There are many more options without a third-row seat.