I am dealing with these same conditions here in Vermont and I've solved the problem by riding single speed. I have two single speed commuters. One is built around a mountain bike frame and is geared low enough to haul groceries, etc in panniers. The other is a lighter, faster bike. It's easier than you might think to ride single speed. If I can do it in these hills (and I'm over 60 commuting 4,000 miles a year) you probably can too. I've never had a breakdown that I couldn't fix with simple tools on the road.