As others have mentioned, last January is a perfect example. It was in the 50s and 60s all week prior to the storm, including the low 60s the day before. I ended up with 13.5"
And yeah not always, but it is far more common for it to be mildish before a snow here, than a nice solid cold air mass already in place.
Edit to add: Completely agree rates are key. And yes we always waste a bunch, but...that's just to be expected.