Yes, you can still use bait stations such as the EZ Klean Rodent Bait Station in winter months. It would be best to remove snow cover so that you can still service the stations and refill bait as needed for best results.
It is recommended that you use 4-6 EZ Klean Rodent Bait Stations around the structure. Place one station at each corner of the structure and, if needed, one by the front entrance and one near the rear entrance.