in some circumstances like this if given notice Motability can arrange for a hire car to be dropped off tat the auto Glass centre, i would give them a call and explain the situation, make sure you tell them it has to be replaced which in turn deems it unsafe and your anxious with the colder weather using the car and waiting any longer than necessary. They may also be able to have your vehicle picked up, it’s a one on one situation/conversation with Motability to sort out.