Montreal?

Traffic in MTL can be a real "adventure". (Lived there for some years back in the day!) If it were me I'd settle for the KOA as it is reasonably close, and then Uber either downtown or to the nearest Metro station. Of course it depends on what you wish to see in the city. For me, it would be the food!

I've never found that campgrounds near major urban cities are all that great. They just do what you need, so if that means a few kids hollering, so be it.

The concerns mostly were because of train noise, not kids etc.

You could try LA CLÉ DES CHAMPS RV RESORT. its just south of Montreal at 15 Montée Saint-Claude, Saint-Philippe, QC, J0L 2K0
website: campinglacledeschamps.com
Phone: 450 659-3389 / 1 877 659-3389
Full Hook ups, 50 amp available

We have stayed here a few times and like it. Easy in & out. Not far from the city but beware: Montreal roads are awful and road repair season has just begun. Cones will be everywhere. Many detours & road closures. Have fun : Camping Alouette
https://campgrounds.rvlife.com/regions/quebec/st-mathieu-de-beloeil/camping-alouette-3989

^^

https://campgrounds.rvlife.com/regions/quebec/st-mathieu-de-beloeil/camping-alouette-3989 when we stayed we took the ferry across the river to visit Montreal/Old Montreal as they have a large commuter lot for parking. If I remember correctly ferry leaves every hour. Campground has directions, worked out well for us.

yeah traffic is heavy around Montreal, especially during commute hrs. As mentioned campground has easy in/out level FHU sites. Park was well maintained.

Everything is urban so you will hear city noise, that said I remember the back part of the park somewhat quieter but don't expect to hear crickets.

2 days visit worked well for us

Mike