Hey Jim, don't have a Channing III, but the cfm output of my Alaska is similar to yours. Based on how my two story set up is working I would say you need more air out of the distribution blower. Mine ramps up to 100% speed when the Tstat is calling for heat (the Coal-trol takes care of that) which has been keeping the upstairs within 2 - 4*F.
Try gradually increasing the output on the distribution fan rheostat until you see a rise in temp upstairs. If it never goes up you may need some additional air circulation. You could put one of those door way corner fans in the hallway opening at the top of the stairs.
Hope you can get the upstairs warm, we might get some real winter weather one of these days!