The selection of a grass seed that compliments your lawn can be a question better suited to your doing some research into what kinds of bluegrass is best for your area.
Usually, to protect your lawn against all hazards, ..drought, heat, overwatering, underwatering, shade, insects, disease....it much better to plant a combination of bluegrass, with added percentage of perennial ryegrass and fescue. Each of the types has their advantages and disadvantages, but the other type/s gives such protection to cover.

The percentage of ryegrass and fescue can be determined by how your lawn is used. If its commonly tracked over, youngsters playing on, dogs romping on, then you might require a higher percentage of the ryegrass, less the bluegrass.
Your local full-service garden nursery should be able to help you.
If you would rather, call your local "extension" service which is usually available at your State funded university.
Their address and phone number is listed in your directory under "state government".
Failing that, any local laboratory that tests soil can be of help.

Not only is a full KBG lawn possible in WI, it is probably the best option except for shadier lawns (those receiving less than 4 hours of direct sun). KBG can tolerate colder winter temps and time under snow cover whereas TTTF is fairly susceptible to snow mold and can get some winter kill. PR also gets winter kill during very cold winters. I personally am not a big fan of mixing PR with other species, as it tends to grow faster and stick up above the other grasses. Plus there is also the issue of allelopathy, or the inhibitory effect PR has on other turfgrass seed germination. KBG can be more shade tolerant than is generally believed. Careful cultivar selection for shade is important. Bewitched is one of the best for shade, and it performs very well in most categories. Nuchicago, like most compact midnights, is not going to do very well in the shade, but within the CM's Award or Liberator would be a better choice for light shade. As far as good CA's for shade, Unique,Bedazzled, Apollo, and Showcase are ones that can tolerate a good amount of shade while producing nice turf.
Overseeding with KBG can be tricky due to its slow germination and establishment. The daily waterings will force your existing grass to grow quickly, often outcompeting KBG seedlings. Mowing as close as possible without harming your existing grass is recommended, and topdressing will help increase seed to soil contact, and ensure your seeds stay moist between waterings. If you have a good amount of thatch and dead grass a power rake might be helpful exposing more soil for your seeds. I would't apply starter fertilizer until you mow your new KBG for the first time, as that will only increase the rate at which your existing grass grows during germination.

Just my $.02: Something to consider is whether the advantages that starter fertilizer has on seed sprouting, rooting and blade developement outweighs the increase in existing grass growth. KBG is notoriusly slow to germinate. The existing grass is going to grow and need cut to alow sunlight to reach the new seeds during the average 3 weeks for KBG germination anyway. If you have topdressed and tread lightly when mowing, there should be minimal seed disturbance and the advantages of starter for new seedlings, in my opinion, outweighs the disadvantages of the increased growth and additional mowing of existing turf.

Thanks for the replies! After reading your suggestions and a little more research, I'm considering going with a blend of Bewitched, Award, and Bedazzled. I think this should do well both in the shade, yet still be alright for those areas in full sun.

I had a terrible issue with thatch, so earlier in the summer, I rented a power rake and dethatched the lawn and then aerated afterwards. There still are a couple spots that seem to have some thatch buildup which I must have not have raked as well, but I can take care of that with a hand rake before sewing the seed.

I may have to research the pros and cons of using a starter fertilizer a bit more before I come to a conclusion on that issue.

Thanks for the help so far guys.

Good luck with the research. If you find something from a reputable source that is factually supported, please post it. So much of what is available, even university turf fact sheets, are cursary and use ininformative terms like vigor and vitality.

Thanks.

Before even posting, that was something I was well aware of. There are so many websites with so much information, each with different information and procedures. I've found the best advice comes from real people who have done it before and are willing to help.

So it looks like I can't find a decent distributor online that sells all 3 types of seed I'm looking for. Williams seed has both the Bewitched and Bedazzled, but that means I would have to find an alternative to the Award I was looking for.

Any suggestions for a replacement or a reputable distributor that sells Award and would be willing to sell in smaller amounts?

Thanks