I hope u got some answers concerning the reseeding of your yard.
Wish i could give u some advice, but i'm not an expert on cool season grasses.
In SC we grow 2 kinds of cool season grasses- fescue and annual rye, but warm season grasses are more common. Generally, when people reseed their lawn here, they pull a "roller thing" (don't know the technical name!) behind a garden tractor. It has spikes on it. It aereates (sp?) the ground and makes small holes. Then they spread their grass
seed. Not sure if that is the proper way to reseed, but that is what many people do here. I also don't know whether it would be best thing to do where u live.
I have a warm season grass (centipede) and it puts out runners and fills in any bare places that might be present. There is no seeding involved.
By the way, i'm curious- what kind of grass
seed are u sowing?
Best of luck with your reseeding project.