Plug or unplug a wall charger when not in use?

Yes! Anker should make a battery wall!!

In the northern-ish parts of the US there are a lot of windmills, because it’s very flat

that is good in winter time: save wood.
Not good in summer time … so unplug in spring, replug in autumn ! :grin:

Even at the moment it would be fine to have such a heater plugged in.
7C outside.