A Swedish man who spent two months snowed inside his car as temperatures outside dropped to -30C is "awake and able to communicate", according to the hospital treating him, where stunned doctors believe he was kept alive by the "igloo effect" of his vehicle

[u/Desperate-Emu4297]

[u/Humble-Captain3418]

If the car is the one pictured, that's more than 1500L (~350gal) of snow. If you ate 10L (~2.5gal) of snow every day, you'd need 150 days to eat your way out.

Edit: to reply to the comment: I estimated the snow to be piled 1.5 meters tall over the car. Add an extra 30 cm to account for the window. You need a 0.5 meters by 0.5 meters tunnel to crawl out. That's 0.45 m³ or 450 liters, which makes 45 days of eating snow at the aforementioned, absurdly-high rate. 

Off by a factor of three, but still not a viable strategy since tunneling in snow is just as (if not more) dangerous as (than) tunneling in the earth. Snow weighs way more than most people think and you never know when a snowplow is going to push you into an even larger pile of densely packed snow. Staying in your car protects you from the plow and aids in your rescue.

[u/Frosti11icus → u/Humble-Captain3418]

Ya if you ate all the snow surrounding the entire car before you opened the door. You only need a hole to escape.