We drive a 2015 Outback with 2 Diono Radian RXT car seats for our 1 and 3 year olds. Works great. Subaru redesigned the Outback in 2015 so it should be the same dimensions as the 2016.
We go on a lot of road trips and occasionally my wife has to sit in the back middle seats to calm the kids down. She can sit right between the 2 car seats without a problem.
Outback has roof racks that fit a box on top no problem. We also attached a trailer hitch, and I haul a trailer to get rid of yard waste, etc. We have gotten very good at minimizing our packing, though, so we barely have to use the roof rack for trips anymore.
The downside with the AWD is that you do have to replace your tires more often. Expect new tires every 40k miles.
Also, even though it is a 4 cylinder engine, the gas mileage is not that great. You also have to use synthetic oil, which makes your oil changes more expensive, albeit less frequent (every 7,500 miles).