Not raining on my parade, I've put larger tires on almost all my vehicles and understand pros and cons. I'm not worried of what might be, I know the benefits gained.
Most cars speedos are already off (set higher than actual).
The gain is ground clearance, looks, going over bumps / pot holes. Other SUVs with 19's use this size tire. The Journey is set more like a car vs SUV - if that's what you like, keep the small tires.
I'm not misleading, tires are on there - not rubbing, etc... The Journey uses a strut that is used on numerous vehicles and includes an unused guide that sticks out past the strut. Simply grind off where it attaches to the strut (about 1/4" wide) or replace strut with model that does not have it. I chose to grind off.