Our D was also in a pre Professional company in HS. She finds the ballet courses as a BA dance major at OU to be not as rigorous as she had in HS (part of it is no en pointe) and she was moved up a level after the course started.
You might check and see which colleges have their own Dance Companies. Miami University (Ohio) does and it even draws people from places like the Cincinnati Ballet. Their company is by audition only and while they do have a dance minor that is primarily for newer students.
http://www.units.miamioh.edu/dancetheatre/the_company/dancers/
On the whole I think larger universities MAY have more opportunities for non dance majors than smaller universities. They will have a larger group of talented young people to draw from. Smaller universities may offer dance majors, however, they often limit their dance opportunities to those in the major.
As for changing your goals concerning engineering, I don’t know what to say. Engineering will give you opportunities career wise that dance won’t. If you want to be an engineer then I think you should look for the best situation for you and you may need to accept some compromises. There are a lot of talented dancers in this country and a lot of schools which offer dance programs of one sort or another so opportunities should not be scarce. You have just narrowed the field considerably by requiring a dance program you can do with engineering. There will still be a lot of schools to consider you just may have to dig deeper and take some time to make some e-mails or phone calls. Good luck.