I killed two hogs with one shot from a .243 with a 100 grain Remington core-lokt a couple of years ago. They both weighed around 100 lbs. They both died side by side. I wasn't trying to do it.
I think it is definitely possible to kill two deer with one shot from an '06, but I wouldn't count on it for a clean kill on both animals. It seems to me there would be a high risk of injuring the second deer and not recovering it.
Just my 2c