The road from culcheth is good - nice and flat, easy bends here and there, pretty quiet.
You're in golborne somewhere, aren't you? For rivington, head up to the crossroads in hindley, straight over and then up to aspull. From there you can go to haigh or blackrod and get to rivington. It's about 8 miles from golborne to aspull, so you wouldn't want to go too much further if you were looking for, say, a 40 mile route, but you could go up rivington or chorley old road or do some of angelzarke/yarrow.
In my experience, places aren't as far away as you might think! Once you get going you can get a surprising distance and get to places you would think we're much too far away. I got to Dunham Massey and back today and in my head that's really distant. Maybe it's because I've only ever really driven there, so in my head it's somewhere you drive to which means its far away.
I'm planning to cycle to my parents on the Wirral sometime next year. It's about 40 miles and I'd have to take the mersey ferry. That'd be quite an adventure.