I ride alone most of the time and ride rural areas (though maybe not as remote as what you're describing). I never feel "unsafe" when I'm out for a ride, but my mom (and several other relatives) really worry about me out riding alone in places where there aren't a whole lot of people around. I think it's probably one of those things where if you just don't feel safe about it or if you're uncomfortable with it---don't do it. I don't even think twice about it and I just go (cuz the alternative is not riding and that's just not an option I care to think about)----but if you have concerns about it, go with your gut.