I would like to see cyclocross in the winter Olympics. That said, the IOC's definition of a winter sport is something that is performed on ice or snow. There are no exceptions that I can think of.It's not snow based, but it is definitely a winter sport. We just have to wait for IOC to grow a brain. That would be like having an extra condition for summer sports that they have to be held at above 30 degrees C without any clouds or don't count.
Cyclocross is very rarely held in icy or snowy conditions. Trying to force the ice/snow element (Val di Sole) can lead to dangerous conditions for riders.
If cyclocross is included in the winter Olympics because it is held in the winter months (in parts of Europe at least -- in North America it is strictly a fall sport) that opens the door to a whole bunch of others.
Another solution is that cycling gets rid of some of the track of BMX medal events and includes CX in the summer Olympics.