One thing you'll want to keep in mind when driving your route, nothing seems like a hill when you're driving but small hills can feel like mountains when you first start out. Really pay close attention to the topography while doing your scouting.

Not long after I first met my wife, we were going to a friends house for Thanksgiving dinner. He lived about 40 miles outside of town. I knew the route to the town where he lived was steadily uphill, meaning I was going to be tired and hungry when I got there. I asked my wife-to-be if there were any hills between the main highway and our friends house so I could be mentally prepared if the last little bit was going to be a tough go (I had never been there before). "No, it's pretty much just a flat curvy road". Perfect I thought. Well seems there was this 1.5 mile 8-9% grade climb on the "flat" curvy road that she never happened to notice in the times that she had been out there which is why I never rely on a driver when I'm curious about how hilly a ride might be.