Its less than 3 hours between canyons, which is why I chose it. There is a train trip in Williams that goes into the Canyon and a bus tour from there, and then a train ride back, so that would be an entire day, say Tuesday, then we take Wednesday and just relax, Thursday head to Bryce, spend the night there(which is why I want to go there, to see the stars, best spot to see them in the US), then head home on Friday.
I think it is doable, at least once we actually get there, and thats the main reason for my asking, the drive between here and there. :)