I lived in Kansas City for awhile and can recommend a few between KC and Denver - you'll want to check out earthriders.org for trail conditions because I think they've had some snow.
In KC, the best two are the Landahl and Swope trails. If you like trails with lots of flow and rocks, they're a good bet. West of KC 30-45 min gets you in range of two KS State parks - Clinton Lake and Perry Lake. Both are longer than the KC trails and are more rugged.
The real gem on I-70, though, is Wilson Lake state park. Right in the middle of KS, it's absolutely fantastic. Of all these, it's probably the least likely to be snowed in, too.