There may be a charity or body, connected with the local church or Scout movement, or even the local GP, or maybe Age Concern ( are they still called that ?) to whom you could turn to find a "Good Samaritan", who would be prepared to come and help you if it snows. This person would be entitled to take road grit from local hoppers and leave it on your premises in ( say ) a bucket, ready for problems.
Alternatively, you can get a roll-out snow/frost mat which is about 10 feet long, which you simply roll out over the snow for people to walk over. It is sold by catalogue - one of those gadget/novelty catalogues which are flooding through front-doors at this time of the year.