Do not count on any scholarships- ROTC is likely to be competitive as are any others. You need to be realistic about finances- for any college. There is NOT always, or usually, a way to work out finances realistically the way to seem to think. You do not want tens/hundreds of thousands of dollars in debt, especially with ordinary college bound stats.
You NEED to discuss matters with your guidance counselor, soon. Scholarships are most often given locally- be sure to find out and apply to all of those available to you at your HS. See if you are eligible for any given by your state as well. Once in college there can be some given out by various departments- but those go only to a very few stellar students.
There will be many, many good college students who go to their instate schools because of finances. This includes students with stats to get into any college, anywhere. It is not the end of the world, or the end of all dreams to go instate. There are many schools you can get a good degree in your proposed major.
btw- Iowa and Wisconsin are two top scoring ACT states (Minnesota trends higher than the national average as well) so your scores will not impress. All three states also have many good options- being instate has many advantages living in Iowa.