If a non-Jew asks if he may shovel your snow on shabbos what is the proper halachic response? Does it make a difference if he is asking to do this for pay (not previously arranged before shabbos)?
The Kitzur Shulchan Aruch (סימן צ - דין עשית חפציו בלא מלאכה ומלאכה על ידי גוי) says that one may not let a non-Jew do any work that one may not do oneself. It's irrelevant of he's being paid or not.
In case of a serious monetary loss, one may hint that the work should be done, but one may not discuss payment. One may make it understood that one who does the job stands to gain.
I.e. If you can't do it, you cannot ask the non-Jew to do it, even before Shabbat.
The next paragraph then says:
Even if the non-Jew comes of his own accord, you have to prevent him from doing anything you are not allowed to do. (All the more so if you actually paid him to come when needed.)
However, as we see in the following paragraph, that if a considerable monetary loss is involved, then one may hint to the non-Jew that he has something to gain by helping you. However, you may not explicitly tell him to do anything you may not do.
So if you risk getting fined - and it's a non-trivial amount - for not clearing the sidewalk, then it would seem you can pay a non-Jew a flat fee for the winter season, and he will come whenever expected.