You joke about the fan but I'd love a keyboard heater for winters. I keep it cold in here to save $ but I have a hard time keeping my hands comfortable.
I can highly recommend it, unless you've got a cat.
Just use any thin and light gaming laptop made in the past 5 years in clamshell mode with the exhaust pointed at your keyboard. That’ll keep one’s hands toasty even doing mundane tasks, those things somehow manage to be space heaters even at moderate load levels.
I bought a electric desk pad from Aliexpress for this reason... helps a bit. But heating the whole room feels better ofc..
How about putting an electric terrarium heater mat under your keyboard? Might that help?
Fingerless gloves are my go-to.
The mouse hand seems to get coldest. Might want to look into that.