Deer tend to congregate more in the fall and winter months and though we don't notice it, deer do migrate in the winter, maybe not the great distances they once did, but they still migrate to a certain degree.
Regarding CWD, here in SoDak it is the most prevelant in the western part of the state, particularily the Black Hills region and we have regulations regarding the transporting and processing of deer killed in CWD counties.
My personal opinion on CWD is that it is the result of the lack of predation to keep the herds culled of the sick and injured deer or elk. So far, there have been no recorded cases of CWD being transmitted to humans, but it can be transmitted to primates, so I would be a little leary of deer or elk taken in a CWD county.