Well this turned out about as well as it could have. Through some searching, I found another user, MiaSakura, that went to Iowa City, the nearest likely option for me and got HRT through a Dr. Nisley. I called the office to see if I needed an updated letter and was told that she doesn't even require one! I've reached out to Mia to thank her, but she hasn't been active in about a year, it appears. Thanks for the help everyone!