If you want to embark on radical change of this kind at least make sure to do it right. A wholesale revision of boundaries or nothing.
This is my view in short.
Either we do a whole-scale consolidation effort to create 3 regions and start from a blank slate with no concern for present regional boundaries, or nothing at all. Since the former isn't politically feasible, the latter it is.
An easy solution, however, which would basically be constitutional as far as I know, would be to set up a joint government for the two regions. Technically, you'd be living in either the Pacific or Midwest and they'd each vote for a Senator but the regional government would be united.