How cold will it get in your garage normally?

I found the oil filled radiators dont work for me in my 24x24' garage, I had 4 going in there and it wouldnt heat it up in the winter.

If you close off an area with blankets and have a heater that will probably be enough though. Also rats are space heaters and heat up ambient a little. (in my case, 1000 ish rats keep the garage about 5-10 degrees warmer than normal, I think