Like I mentioned in the OP, it's a Squier Jazzmaster, so satin maple neck and a rosewood board. I oil it every time I change strings, which is just a few times a year since I use Elixirs. I don't know for sure how dry it got in my house last winter, since I bought the humidity meter after I got a small humidifier, but it was dry enough that I was getting fret sprout and had to get the fret ends filed down. Now that that's fixed, I'm wondering if the guitar could handle the dryer air, but would rather not take any chances, because I can't afford to start accruing avoidable expenses right now.
I work at a college so it's a big building that gets super dry in the winter. Allegedly the air gets replaced like 10 times a day, which is why I'm not sure if this little gallon humidifier would make a difference.
I got a 4-gallon "whole home" humidifier off Amazon for the house earlier this season. I don't know how much it gets upstairs, but it keeps our main floor around 40-50%, depending on how close you are to it. This one lets you set a target humidity and it runs itself when it needs to. Right now I'd say it runs about 1/3-1/2 of the time around the clock, and is pumping 1.5-2 gallons of water into the air a day.