Unless it's really really cold here for us, and that usually means 30s for us, I have a door or 2 open. My house doesn't have central, forced air heat. It's old. Fl builders didn't think it was necessary 60 plus years ago. We only get a week or two of nasty, in Jan.

So the humidity in and out is usually about the same.

Aug & Sept are brutal here, but I'm never cold then!

One thing I do when showering is to pull the tub drain and let the tub fill. My frozen feet thaw from what normally goes down immediately.