I'd say the biggest potential downside of making changes to your major in the current landscape at large universities is the negative financial impact. In many cases, you can change but you may need to take a substantial number of different general pre-requisite classes that are required to be accepted into your major. That can be expensive. And in the worst cases, there are some instances where you must enter a major degree granting program on day one of college life and there is no option to transfer into the major later. Ages ago when I was a student, swapping back and forth between majors was more routine or at least less costly than it is now. The primary change has been driven by somewhat intense employer pressure put on academic institutions to prepare grads with more specific career experience due to the large influx of students with degrees on the job market. That lead many college departments within major universities to reluctantly mandate a much more refined set of general ed courses that are needed for acceptance into the degree granting program. bottom line, its become much less common for students to be able to take a wide selection of general education course for their first two years as a means to explore options, preferences, etc prior to picking a major. now having said that, in cases where it will work, i think theres benefits for some to attending the first two years at a smaller 2 year institution and then transfering into a larger college.
But the real issue at hand beyond finances is the what is going to work for your daughter or any person heading off to school. As many have stated above, a big school is not for everyone and the rigor of the courses often is only a tiny part of the equation. The student has to want it, be prepared for it and maybe most importantly be skilled at acquiring the resources needed to navigate it once there. Each one of the big universities has its own unique character but they are also very similar in many regards. Very large academic institutions, particularly those with highly rated progrms, tend to be held in high regard by many employers and even more so by graduate degree programs . That may or may not be important to your daughter. On the flip side of the coin, really big universities also amount to decent sized cities with everything that is involved with a city. You should be able to pull the UW annual safety report and you'll get a small glimpse at the actual dangers lurking there for a 18 year old. Make no mistake, there are real dangers.
All big academic institutions have tons of data to predict probabilities of student success vs trouble achieving academic success. However, only your family and daughter will really be able to know if the UW Madison setting is a good fit. I can tell you that a Big 10 university was one heck of an adjustment for me at 18. Somehow i made it thru but it was sketchy at times .
