Winters are very cold. Roads can get icy and dangerous. Snow and strong winds can create whiteouts with zero visibilty on Wyoming highways. Call ahead for road conditions before driving on a snowy day.
Make sure you reserve early for Laramie, WY. We have several colleges and one of them has a graduation every 3 months. This means that every three months for about a week, it's very hard to get a hotel room. Cheyenne frontier days and UW's graduation are aslo bad times to procure a room.