I'm assuming that you're not staying in town because most places have their own parking.

There is Cliff Walk access pretty close to some of the mansions. You can definitely park in those lots (at least those that are part of the Newport Restoration Foundation, the most well known ones)and get to the center of the walk and go in either direction. You can also often find parking on the side streets near the mansions. I've always found parking on the street leading up to the 40 steps.

If by "downtown" you mean the wharf area, it's a little far for some people to walk, but still possible depending on which mansion you park at.You can also park on Thames Street at the far end away from the main harbor areas (near the Yacht Restoration School) where street traffic thins out a little

There's also the Brick Market Place "downtown" which is also doable on foot. I find it hard to park in that area because of the small and crooked streets.

There's easy inexpensive all day parking at the Visitor Center which is also the main bus station. You can take buses and trolleys from there too.

I prefer Newport off season but rarely find it completely impossible to get around. Those times are mostly festivals like the folk festival or the America's cup races etc

Thanks - very good info.

If we go Labor Day we won't be able to stay in Newport itself - everything is booked. So now I'm think waiting a few weeks. Do you think there will be enough difference in terms of crowds to make it worth putting it off - I'm also finding much more availability mid September. But whichever we do, now I know where to park - so thanks.