My old man was a fire fighter for years and he always advocated shoveling a path around the entire house at least as wide as 3 or 4 shovel widths. He had a story (true or not) about an emergency that got much worse because they couldn't access the rear of the building due to snow.

Maybe some fire fighter somewhere will tell me otherwise. My father is a piece of shit and a notorious bullshit artist. But it at least passes the sniff test and years later I continue shoveling around my property.