Welcome aboard, Matt!
I have plenty of experience driving in bad weather--hey I'm a life-long Chicagoan!. Few people know snow and ice better than we do (except for maybe Buffaloians and Minnesotans). When I bought my 323i, the xi wasn't out yet, so I didn't have a choice. After worrying about snow-driving performance, I used to swap winters and summers for the first couple of years, but I grew tired of it and eventually just with all-seasons. Anyways, I can tell with 100% seriousness that i have never had any problems slipping or sliding into a ditch during snow or ice situations. Rain is not even really an issue. I have to watch my revs more closely when starting out (I have a manual), but hey, what's wrong with paying a little more attention in poor weather.
I don't think you need AWD for Ohio; I'm guessing the winters are about equal with Chicago, if not milder. Also, keep in mind that the 5er (until this year) and 7er are all RWD. You think people stop driving those cars in the winter? Nope. I see plenty of 7ers, and even Lexus LS's (also only RWD) floating around during winter time. The smart traction control systems available on RWD cars are amazing. Read some reviews for the GS430--which is RWD. I read a Canadian review which said they would be perfectly comfortable cruising around with GS43 provided it all all-seasons or even snows.
I think responsible, cautious driving goes a long way when it comes to bad-weather driving. ..