I do not have time to respond now other than to say I just visited UW-Eau Claire & University of Minnesota.
I love the University of Minnesota. Many years ago, it was the second university to which one of ours was accepted, but ultimately did not attend. Great school with an exciting atmosphere & vibrant city with lots of attractive career / job opportunities.
I will offer cautionary advice similar to that offered above: Relationships can & do change. What if you & your boyfriend break up ? Will you still be happy with your decision to transfer ?
Otherwise, transferring seems as though it might be a good move for you if you want to experience a larger, highly respected school in a major US city. Also, the gender imbalance at UW-Eau Claire may be another factor to consider. More balance at the University of Minnesota. T/C.
What does your boyfriend think about your plans ? Important since you intend to live together. Understand that if you do transfer, then you are pushing the relationship to a new level which forces each person in the relationship to reassess his or her readiness to fully commit at such a young age.