Can you tell us which university you would be planning to transfer to? If we knew which schools we were talking about it might allow us to give more accurate advice.
In my job I see very good graduates from a wide range of universities doing very well. I spent some time (and got two degrees) at highly ranked universities and I agree that they are not a good fit for every strong student. Just because you can do the academic work does not imply that you would want to be a student at a highly ranked school. Also, university rankings are based on some specific criteria, but those criteria say very little about which school will be a good fit for you or me or my kids.
My inclination would be to send in your transfer applications now. Then decide when you start getting acceptances.
Meanwhile you also might want to look into spending a year abroad next year as another option.