I'd go with a good point and shoot, myself. Nothing spoils a hike or bike trip for me more than lugging a bunch of heavy photo gear along.
If you want to take full advantage of your 7D and super sharp zoom, you will also need to bring a sturdy tripod. Kinda defeats the purpose of leaving the car behind, if you ask me.
As an intermediate option, an 18 MP Rebel would be good. I've carried one on my motorcycle trips with the 18-50 stabilized kit lens. Daylight shots look fantastic and you can bring a lightweight tripod if you want to do some night shots.