It sounds like we have similar feelings about travel. I don't mind driving and parking in a new town. We view it as an adventure rather than a chore! Coming downtown from any direction will get you to a parking ramp fairly easily. If they all end up being full, there is street parking, or you can park a few blocks away, down the hill from the Capitol, on the side streets on the east side in particular, for free, and then hike up the hill to the art fair.
The La Quinta, which is ranked very highly on TripAdvisor, is in the American Center area. That's what made me recommend it. There are other hotels out there, too. Weekend rates tend to be good, since they are office park hotels that need customers on the weekends.
It is also close enough that you can head back if you need a break from all the sensory overload that is our art fair.
The main traffic problem in Madison in the summer is always construction. That is the only traffic consideration when it is not rush hour. I grew up out East, so to me, Madison traffic is a minor nuisance sometimes. For the most part, you might hit a rough patch but it's usually an accident or something that is making people slow down and look. We are still a small city, and not like Milwaukee.
If you are from a small town, Madison may seem to have traffic problems, but for the most part, it moves pretty well, and the streets are easy to follow on a map or a Garmin, at least until you get to the downtown Capitol area. Then they circle the square and one-way streets are more common. Much of the central city is grid-like, so it's easy to go right or left and take a parallel street around any snarl you find in front of you.
You will have no problem finding good coffee downtown on State Street in particular. We have four or five locally owned shops there with various baked goods and simple breakfast or lunch items. The Memorial Union has a Peet's Coffee shop in it, if you are venturing down to the campus.
And you can find live music in restaurants on the weekend, too, especially in the summer when we have so many visitors from elsewhere. You can look at thedailypage.com to see what is going on the next weekend, and there is a restaurant guide there, too. It divides Madison into sections, and you can choose which meal you are looking for and what type of cuisine if you like ethnic restaurants.
There are galleries and art museums on State Street and the University campus, so if the weather is not to your liking, you can get out of the sun or rain and look at art at the Overture Center or Fannie Garver on State, or at the Chazen museum on University.
I'm sure you will enjoy your visit, and keep asking questions!