Cats and winter cold

Hi All -

If this is answered in an FAQ (I couldn't find one), please let me know
where I can find the FAQs.

I have a Himalayan cat and live in the Sacramento Valley.

The cat likes to be outside 95% of the time and sleeps in the (unheated)
garage.

It gets down below freezing during the night in the winter, and I'm
concerned whether that is too cold and how to keep the cat warm.

I have a pets' heating pad (similar to a human's heating pad, but not as
warm) that the cat stays on at night, which I'm sure helps somewhat.

Does anyone have advice as to how cold is too cold?

Are there any tricks for providing a way for the cat to keep herself warm?

Thanks!