While it is true that whitetails need to pack on carbs this time of year. You will see that deer are opportunists' first and foremost. They are browsers.

An example of this is happening right now where I live in northern Illinois. The deer are walking through the cut corn fields which are under 5"+ of snow and making their way towards hay fields where stalks protrude well above the snow line. As the snow melts I know (through past years) how quickly they will move back to corn.

So it may depend on where you are before you can make that call.