Considering that the Inuit use .223's for Polar bear, Grizzly, Moose, and Caribou I'm sure it will work on those northern deer as well.
Yeah, but they typically take head or neck shots. Most people in the lower 48 shoot deer in the body. I don't care for any caliber where the weight of the bullets drop significantly below 100 grains for deer or larger sized game. That makes the .243 my low end limit for deer.