This would be the best plan, I think. I live in urban squalor -- oh I literally have scars from a couple muggings, sir, one of which was more a multi-bad-guy attempt kidnap/murder than a mugging -- and often dream of the Land O' Lakes or similar, but there are trade-offs everywhere. Personally I think you're better off in such geography waiting on an iPhone than where I live with an iPhone and excellent coverage.
I checked your profile, you don't list your age, but I'm old enough to remember the big ATT break-up anti-monopoly action by the US government. And ever since then, accelerating lately at a rapid rate, ATT has been trying to piece back together their former total dominance of American telecommunications. Frightening for some, beneficial for you, as they are trying get first-party coverage in every nook and cranny of this country as fast as possible.
I suggest enlisting a few of your friends and all of you call ATT every week and tell them, "It's aboat time you covered voice and EDGE in Marshall, MN, as we need to coordinate our daily luncheons at the boofay on iPhones". Repeat until you get good coverage out there.
Stupid thing is, we have stellar coverage here in Dallas: 190kpbs EDGE speeds, even from inside our townhouse which has some whacko radio interference (read, old guy with ancient shortwave set bleeding signal all over the spectrum) around it. But besides mine, my wife's and at an Apple Store, I just saw my first other iPhone in the wild last night. People don't pick up on things too fast around here.
p.s. I couldn't resist the phonetically spelled accent gag. I hope I didn't offend you. I really do love MN. I was once in love with a girl whose sister had met and married a man in M/St. Paul, relocating to be with him. The worst part of my break-up with that girl was that I no longer had regular excuses to visit with MN with nice, free lodging and total access to her brother-in-law's powerboat. Really, this guy was so nice he would have had me up a few times a year, even after the family-ish sort of connections were gone, just like almost all the Minnesotans I met on my trips. But I wasn't sure about the diplomacy of doing that.
p.p.s. Like I said, if I think of a workaround, I'll let you know. I wouldn't buy an iPod touch if you're holding out for an iPhone -- totally redundant the touch, with few features even -- and there's not much sense activating an iPhone with ATT and just never using the phone/date features while paying $60 a month for the minimum plan.