I wanted to let you all know how things turned out...
I did indeed get an offer from my 2nd choice program at the beginning of last week, just a few days after my interview with my 1st choice program.
I took your advice and asked for a few days to talk with my fiance about it. In the meantime, I contacted my 1st choice and let them know that I had another offer, but preferred them.
My 1st choice program contacted me right away and let me know that they planned to rank me (they don't pre-match apparently). After getting a reassuring phone call with the 1st choice program director, I turned down my 2nd choice program and submitted my match list with only the 1st choice program on it.
Of course, I realize this is a tiny bit of a risk, but I feel really comfortable that they will stand by their word. So, it looks like everything has turned out perfectly!
Thanks again for all your help through this process. I really didn't know where to begin, and you guys saved me! 👍