wat do i do, when the tire pressure indicator is on, ? do i take my z to the nearest gasstation and fill up the tires? btw, i live in edmonton,ab canada. its -20 here

 

first manually check the air pressure ...

 

You should ignore it. The tires will fill themselves back up this coming Spring. That is, assuming you can wait that long.

For every ten degrees the temps drop, you can expect to lose one PSI in your tires. If the temps drop overnight, even in a garage, you should expect some loss.