For the record, I know of no countries that require studded snow tires. Snow tires, yes, studded, no. Snow tires really do make the driving feel safer.
If the roads aren't cleared before your gig, and you don't feel like you can drive safely, cancel. Otherwise, drive like an old lady. And I agree that calling to confirm before you set out is a good idea. If you're thinking about cancelling, so are the patrons.