I have an outside shoot tomorrow in single-digit temperatures. Any recommendations for camera and lens. Do I need to slowly get it accustomed to the temperature or can I go directly from room temp to quite cold?
Going from warm to cold is fine. You need to be careful when taking a cold camera into a warm environment because condensation will form. Best is to put the camera in a drybag or other sealed case before going inside and leave it there until it warms up to the temperature of the room. I've been shooting in temperatures below freezing with my C100 for the past two weeks without issue other than reduced battery life.
I haven't shot in below freezing temperatures with the C300 till date, however, I have had temperatures of 2-5 degrees in a number of days especially while waiting for the leopard before dawn. No problem at all. If you are immediately moving into warm temperature of car/room, better to put it in a ziplock or a camera bag