Hi Fifi,
Am I right in thinking your goats are Cashmere or Angora? If they are, and they have the access you have mentioned to the barn they should be fine. If they are pregnant I would start shutting them in at night so it is warmer for them, but unless there is lots of snow on the ground, or the ground is really damp, I would let them go out during the day for a good while yet.
Beth