Saturn won't start in the cold

My daughter has a 2000 Saturn SL 2 that sits in a college parking lot overnight in Wisconsin. When the tempurature dips below 0 the car will not start. We have poured gallons of Heet into the tank and run through several tanks of fuel theoretically purging the system of any moisture, her mechanic has performed a tune-up including new plugs, timing etc. and installed a new battery. The car turns over just fine but will not start in the extremly cold weather. Can there be a problem with the fuel pump or filter? Or are there any other ideas, my daughter needs to get to work to help pay for her education! I can’t afford to have her return home and expect to be fed, clothed and all of that expense, I can’t even afford her taste in clothes. She must be educated! The cost of the repair will be far cheaper, whatever that cost is.

One of the first and easiest things to check is the Coolant Temp Sensor (CTS). It’s easily checked with a voltmeter. It’s supposed to tell the car’s computer whether the engine is cold or warmed up, so the computer will adjust the rpms/fuel ratio accordingly.
If the car is cold, then the CTS should have crazy high resistance. Once warmed up, the number should drop significantly. If that’s not the case, then you should change it out (it costs, like, 5 bucks).

*** I’m sorry, 8.99 at Autozone.

Thanks for the help, I will follow up and check this out tomorrow, temps are supposed to be in the mid 30’s which means it will probably start. Hopefully, your suggestion may lead to a permanent cure though.