Yes, you can as long as you remember that electronics that require power can drain a battery to exhaustion much faster in cold temperatures then they would when it's warm. This is especially true for GOTO telescopes who use significant amounts of power. Bring an extra power tank or battery along, and make sure to have dew heaters on the finder scope, diagonal mirror if your telescope has an open tube and on the corrector or objective lens if you have a catadioptric or refracting telescope. Otherwise frost can form and shut you down for the night. Dress very warmly, as though it's 20 or 30 degree colder than the thermometer indicates because you won't be moving much and generating much heat. Pay particular attention to keeping your head, feet and hands warm. You don't want to touch freezing metal when it's 10 below outside barehanded. Make sure your vehicle is dependable. I advise against going out into the hinterlands in sub-zero cold or cold weather mixed with strong winds because death can occur within minutes out there from hypothermia. When it's 50 below, I would either observe from home, or not at all. That is deadly cold weather to be outside for any reason. Not only that, lubricants can solidify, motors can stop working and batteries can fail in killing cold like that. Not even animals go out in that if they have a choice. It can be really hard to observe when it 20 degree above zero between the gusty wind and the dampness that occurs here in the Southern U.S. Know what the warning signs of hypothermia are also, it can sneak up on you and before you know it, you're in deep trouble. The first sign is suddenly feeling very warm all over, then confusion and disorientation sets in. At least take along a sleeping bag and extra clothes and let someone know where you're going and when you're coming back. Take along a mobile phone too, it could be the difference between getting home and a long unpleasant stay in the frigid outdoors at best. Make sure your vehicle can handle the terrain you're driving over. Needless to say, a small front-wheel drive car will get stuck on ice covered ground full or ruts, which is the norm when you're taking to unpaved roads or worse. Merely freezing temperatures can be accommodated with little difficulty, but be careful. I do more observing in the winter than any other time because the skies are darkest and the nights longest. With dew heaters on my telescope, a powerful battery that can cope with both the cold and the load placed on it and multiple layers of clothing and warm boots suited to the weather, I have no problem observing all night long when the temperatures are near freezing. The coldest weather I ever observed in was around zero degrees, after two hours of which I was forced to quit because my hands and feet started to freeze. Taking a thermos full of coffee or hot chocolate also helps keep you warm, as well as some snacks.