To answer your question of concern, the odds of you moving out of the district, let alone group, is small. From my experience with interns, positions are only offered on an "As needed" basis, meaning if the store/district/group has an opening then they can offer a position. It is the store/district/group offering you the internship/job, not corporate Target. Corporate Target sets jobs up then hands them down to the individual district to make the call. Each group operates differently and follows their own standards for the hiring process. You may be the best Target has ever seen in District A, however District B doesn't know you from Adam. To give you an idea on moving nationwide at the ETL-STL level, one of our best ETLs (12 years) wanted to transfer to his home state. He's been in several ETL positions and is always tasked for special assignments to turn a red store green. A week before his expected date to leave (which he was approved to transfer), he got denied. He already moved his family and Target personnel at our district said he will not be moving stores (this was before the credit-card crisis). You'll probably have to build up a good background (18-36 months) as an ETL before being able to move to a market of choice, unless the market of choice is doing poorly or needs leaders.
Nobiliscus is right about not being scared away. These posts are based from our personal views and experiences with Target. When it comes to a retail career, Target is not entirely horrible. There are better retail companies and there are far worse. It just depends on what you are looking for in a career and how you plan on applying your degree. First, to be an ETL it does not require a degree to be successful. Actually you may feel like you are wasting your talent/education. Honestly, at the end of the day you sell toilet paper, nail polish, dog food, and other crap people don't need. Sometimes the reward is not worth the cost.
If you're interested in an HR career field, Target is a great stepping stone (as long as you are offered a position in HR). You may internship for HR but get offered a different position, completely unrelated to HR. Another pitfall of HR at Target, you're not a true HR representative. You are put into a position where you are no longer a third party entity that employees can go to. How can an LOD properly take a neutral side if you also have to worry about TMs performance? Our ETL-HR pulled too many LOD shifts to take a neutral position. The position was better filled by the HR-TL who truly did have a neutral stance, however that position has little HR authority.
I enjoyed my time with Target. I was an ETL-Logistics working at a two-story AA+ store with an overnight flow process. The work was easy but it was also unrewarding and time consuming. My STL expected overnight ETLs to work 60+ hours regardless of how well we were doing. Also, overnight had to consume the work dayside could not complete but I was held responsible if the extra work kept us from meeting our goal times. Life would have been easier if I was single and drank on my days off.
Prior to Target I was in the military. Now I am a software engineer for the federal government (my degree is in Business). I enjoy working 8 hours a day, 5 days a week with the option to work 2-3 days from home. I have holidays off and get to enjoy every weekend with my family. And to top it off, my salary is higher than it was with Target (even my bonuses are higher). Even if I had a lower salary, lower stress and weekends off are invaluable.
My suggestion if you are an HR major or business major with HR interest: Internship somewhere else. The internship is like being a glorified high school graduate who was given keys to the register and a walkie, not too impressive. There are tons of HR jobs on the market where I live (DMV). Or complete the internship, get HR experience, then work for a company with a better work/life balance.
Or as Nobiliscus said "So long as you're up for the politics and challenge, you'll enjoy the work". Play the politics of Target and you'll do well. Drink the punch, sleep in red/khaki, become best friends with STL, sleeping with the STL/DTL is automatic career booster, become a Target Cheerleader, etc. Make it look like everything Target does is infallible and live by best practice, you'll do great. The only challenge...dealing with all the BS that comes with the position.