@guccigarlic here are the admission rates for the past 10 years (2016 data not yet available but hopefully will be soon). Check out page three to compare in-state to out-of-state rates:
https://apir.wisc.edu/admissions/New_Freshmen_Applicants.pdf
Your ACT is fantastic and should make up for the lower GPA; however, concerns about the direction of your grades are spot on and that will 100% be something brought up by the admissions committee. High likelihood you will need to send in your mid-year senior grades in order to get an admission. However, it’s not clear that you should skip the EA deadline and apply RD. First of all, space is going to be limited for the second deadline and you will be up against a whole lot of people who already specified an interest in UW but were deferred from EA. Second, very few schools would reject a 35 ACT outright. More likely they will give you a chance to turn it around.
Check out last year’s admission thread to get an idea of the stats of those accepted and postponed from first-round admission. Starting around Comment #1192: http://talk.collegeconfidential.com/university-wisconsin-madison/1813608-uw-madison-fall-2016-decisions-p80.html
There are lots of examples of postponements and even accepted with stats similar to yours, or even a bit lower. Therefore, you are probably OK to apply first round (11/1 deadline) but make sure your essay knocks it out of the park and that you have a strong rec. letter from a teacher who can verify your academic strength. And there is no room for error senior year: you must turn around the direction of your grades or you will not be perceived as able to handle the workload at a UW or comparable school. Talk to an adult who can help you make this happen (a teacher, a parent, a doctor, someone appropriate for whatever the issue is).
Good luck to you!