We had the same issue at work. To get around it, we hired a couple of 4WD Volvo's, and anyone who can't come in can be picked up. We can't run the presses with no bodies, so taking Holiday's (paid or not) aren't the answer. A bit of caring for your staff gets around all the unpleasantness.
It's worth remebering though, that Employment law says that if they need to look after dependents, like when schools are closed, that can't be forced to be a Holiday.