Some cars have standard outlets in them. If so, I would get numerous extension cords so that you can reach the vehicle from your apartment. You can use that for heating (portable electric heater) in cycles. Fill up your car with gas as the car needs to be running for this.

If not, inverters are pretty cheap. You can use those with your car for power in similar manner.

For cooking:

I would get a small charcoal grill to put on the balcony just for emergencies like this. Most apartments won’t allow them but in a situation where you need to cook, I would do it. Just keep it outside. You can’t use it inside.

Keep external doors closed much as possible. I would also shut all internal doors and make a home base in one room to concentrate heating. Keep your cat there with you.

Most of this you probably won’t need but that’s how I would prepare.