Next time you feel like being obnoxiously passive aggressive when someone asks for help, maybe do everyone a favor and don't.
I for one am grateful the OP asked this question as our temps are dropping as well and it made me check my tire pressure. Sure enough on two wheels I was within 1 PSI of the TPMS warning triggering. I'm glad I checked the tire pressure on all 4 wheels to avoid seeing a TPMS warning when I'm on my way somewhere or confusing my wife if she was driving somewhere.
With the temps falling, I suggest everyone check their tire pressure as well and I recommend that you keep a small portable air compressor in the car. It might even save you one day if you have a "slow puncture/leak."
To the OP: This is probably your first winter with the car and the fact that you are getting the warning on all 3 wheels suggests this is due to the dropping temps, as you are seeing a consistent drop on 3 wheels. Just add some air and you should be fine.
There has been varying PSI numbers suggested over the last several years so I don't mind this topic being brought up. The consensus for now seems to be 45 psi and possibly reduce that by 2-3 psi for comfort if you decide you prefer that. Ambient temperatures does affect the tire pressure so in my case, I set all four tires to 44 psi.
As always, keep an eye on tire pressure and tire wear about once a month.