Ask yourself a question. Do you walk in from the snow and salt with your wellies on, across the lounge carpet? Or do you take them off at the front door?
Depends on what sort of customers you're aiming at really. I have had a few customers saying after the cold snaps that they hung on till the snow went, but plenty others still having the work done.
I would say commercial customers would be more averse to having carpet cleaning done in the middle of a snowy spell.