I rented a Canon 500mm f/4L IS from lensrentals.com for two weeks and took advantage of the cold weather to go searching for eagles along the Mississippi river. The first weekend I spent in Red Wing, Reed's Landing and Wabasha, MN as well as La Crosse, WI. The second weekend I went further down the Mississippi to some of the locks and dams near the Quad Cities of IA and IL.
It turns out that during my safari, we had some the coldest weather here in a couple of years. On Feb 3, the day I spent in La Crosse, WI, the temperature never got above zero and wind chills were in the 20s below. I didn't spend much time outside of the vehicle, but those times I did venture out with my tripod, the wind made my eyes water and then my eyelashes froze! The second weekend was also cold, but not quite as bad. Of course, this is all good for finding eagles, which tend to congregate near any areas of open water they can find. Most of the rivers are frozen, so open water can be found near power plants and the locks and dams along the river and that's where eagles can be found.