Thanks to all, as gaining different objective perspectives has been really helpful as I try to wade through all of this. I'll try to address several points that previous posters have brought up:
1)It's funny that someone brought up having my wife tell me what her ideal plan would be. I actually did just that last night. Her answer: I don't want to move, I don't think I even want you to just quit, I just want things to stay exactly the way they are. My pointing out that this is no longer possible fell on deaf ears.
2)Sadly, she has refused counseling, although I admit that I hadn't considered the possibility of going to counseling alone.
3) I can see how someone might look at my initial desire to quit and say "marriage >>>>helping people." Actually, the further this goes, the more I remember that the reason I went into medicine in the first place is to help people, and the more I'm reminded of that, the stronger my resolve to push on. There is a particular population under duress that I wish to gear my medical career toward helping, which is a cause I have always been passionate about. As you can imagine, attempts to explain this to my wife were received as "getting on my high horse" and "thinking my career is so much more important than hers."
4) I tried to revisit the idea that at one point, my wife had kind of, sort of approved this place… at least to the greatest degree I could get her to approve any place that wasn't here. (Note that she has NEVER been there- with kids, it's hard to do couples interview travel.) She simply said that she didn't know how she'd feel about moving until she was staring it in the face.
She also said that, while she loves me, she has derived an enormous amount of satisfaction from her own career, especially since I have obviously often had to study, be on call, etc. during med school. She perceives that during residency, I'd be even more tied up and she'd have lost the satisfaction she gets from her career that has made this livable. She also feels that me expecting her to leave our current situation would be the equivalent of her telling me I needed to choose between her and medicine, which she isn't actually trying to do. My take on that: I did not ASK for this either- in fact, I did everything possible to avoid it. When choosing med schools, I happily passed up a much more prestigious (and cheaper!) school in a distant city for the sake of our family. I don't mean to use this as collateral, because it didn't feel like a sacrifice given that it was best for my family, and I'd happily make the same decision again in a heartbeat.
It is true that my response to conflict has usually been just to give in because it's "easier for everyone." If you can stay COMPLETELY consistent with that strategy, it works great, until life deals you a hand you can't reasonably change. It also covers up the fact that you don't have adequate conflict resolution skills in the relationship, and that you haven't primed your SO to respect you as an equal.