The Butts is an absolutely ideal location for a new ground but it will never happen. The building work currently going on completely rules it out. Prior to that it might just have been possible to come up with a plan that would have worked for a smaller stadium than the Ricoh but no chance now.
And of course besides the problems of actually building the thing we would have to deal with CCC who own the place.
If, and its a huge if, we are to get a new ground we're probably looking at someone just over the city boundary, such as by Ansty Park, Warwick Uni or Broadstreet. Can't see any reason CRFC would want to move away from the city centre to any new ground we may build.