I would suggest you ask the guy at yoru local full-service nursery....or....call the Extension Service of your local STATE funded university and ask when is the last date when grass seed can be expected to germinate before winter's frost arrives.
Southern Wisconsin is a zone 5....northern parts...zone 4....
and as such, it is commonly held that September 1st, is the last date to consider seeding a lawn and expect it to germinate in time.
Sodding.....now that's a different equation.....sod can be put down as late as November in some areas of the north.
Sod roots will take as long as the soil temperature is above 40ú F.
A good hard raking will usually get rid of dead grass.
Do it first....north to south.....then go back and repeat east to west.
This opens the soil to your seed and its easier to have it sit on the soil when you sprinkle.

Its a choice...some put straw over the seed---others put down peat moss while others don't do anything.
If straw....make sure its at least two years old.....
straw has seeds....it wouldn't do to try to grow a lawn and end up with a meadow.

Also, you might ask about using a seed starting fertilizer when you spread it.

Extension services can be found in your BLUE pages of your telephone book under STATE GOVERNMENT...