ahhhh yes... tough stuff, I have to say. Most of my interviews had one day in between (ex. Fly out on a Monday, interview Tuesday, half day at work on Wednesday, fly out Wednesday night, interview Thursday, fly home Thursday night, work Friday, collapse, rinse, repeat... 😉 ) But, as I'm reading here, this situation seems pretty common. More than likely, most of your fellow interviewees will be in the same situation. So, do your best to remain as rested as possible (in my experience, I was always more rested when I stayed in a hotel as opposed to w/ a student, although my bank account is reflective of that now... weigh pros and cons on that one I guess...)
Also, if at all possible, DEFINITELY leave a day in between. I flew home after one interview, and the next morning was on the subway traveling to a second. Not only did I not even have 6 hours between when I got home to when I was out the door again for interview #2, but my mind got all jumbled w/ details from both schools. Not a good situation. So yeah, you can do it, definitely do your research (maps, transportation etc) ahead of time, and stay rested as much as possible... and bring lots of munchies... 😀