if its agreed upon ahead of time.
my agreement with all my snow removal clients is 2" or greater. that doesn't mean let the 2" fall and wait and see if its going to melt. I would get started on who I could and stop once it started to melt.
in fact I've done this before. I've started a route only to have it warm up and start to melt. some paid for service others did not. no one was upset.
but hey I guess I'm just the guy down the street so what do I know......