At my previous property, I went for a dense screen with the cheapest 'hedge cedar' on sale, 3'- 4' specimens planted on 2' centers. I had 2 neighbors in the back with an existing fence in a straight line, I planted 2' from the back fence. I planted on the lot line with my side neighbors as there were no side fences at the then new development.

The dense planting draws the hedge trees up rather than sideways. It took only 7 or 8 years until they were 1 storey tall, they are now 2 storeys tall with a width of about 5' to 7' at the base. In particular, there is very little overhang over the back fence, the neighbors at the back never complained.

The hedge grew too tall to shear even before I left. The unsheared hedge does splay here and there under heavy snowload, but I never had any branch breakage even under the heaviest snowloads, presumably because the dense planting intermingles the branches, thereby supporting each other. The splayed hedge always became smooth by itself in spring without me doing anything.

The hedge shelters birds. In particular, it allows Northern Cardinals and American Robins to overwinter at higher latitudes than they normally would. The birds enliven the white desert in the winter backyard like nothing else can.

In the last half dozen of years I was there, the hedge created a nice, almost woodland type of micro-climate. The backyard was nice and cool in even the hottest summer days, although there were mosquitoes too. The lawn only needed 3 or 4 mowings per season.

Somebody else in a different part of the town had a dense hedge of the (also popular) 'Emerald Green' cultivar at maybe 20x the cost if not more. It has a darker green color, but not necessarily better looking. It got diseased or pest-infested, not sure which, the entire hedge died out completely within 3 seasons.

It can happen with any mono-culture of course, but I think your best bet is also one of the cheapest solutions with hedge cedars harvested in the wild, emulating a local Thuja forest in your backyard. Good luck!