My dad and I are here in the RVA area. We really enjoy taking the Cardinal west, but as you may know AGR has a dividing line at Cincinnati and Cleveland, so it's tough to go out without using a ton of points. Next week, for example, we were able to route ourselves "west" by way of CLP-NYP (Crescent), NYP-CHI (LSL), then the Cardinal CHI-CLP. Of course, this is 20,000 pts both ways, but it is an efficient way to spend the time.
When it comes to getting to CHI and back, there really isn't a good way to do it on that points total - you'd end up spending 20k on one night on the train. For example, for that same redemption you could ride from El Paso, TX to Chicago, ELP-LAX-PDX-CHI using the Sunset Ltd, Coast Starlight, and Empire Builder and spending five days/four nights aboard the train. We try to be as efficient as possible and get the most for our points.
If you want to know any more of the good routes, feel free to PM me and I can fill you in. I feel like I've spent hours trying to make it work for some trip we've done!