6 month old puppy obsessed with going upstairs and outside

We adopted a six month old puppy to add to our family. We adopted our last dog over five years ago from the same rescue, but he was a couple months younger, so all of his training came from scratch. She is mostly potty trained and crate trained. We’re trying to learn her tells for going to the bathroom so whenever she goes to the back door we take her out, but she’s getting to the point where she just likes being outside, despite the snow that we have, so I’m struggling with wanting to take her out whenever she walks to the door versus when she actually has to go to the bathroom. We’re also still trying to learn her poop schedule so even if she peed five minutes ago and goes to the door, I don’t want to ignore it and risk her pooping in the house. Related (?): she’s obsessed with going upstairs when we all typically spend our time in the basement. We started closing the door at the top of the stairs so she can’t go up there by herself, but sometimes she’ll run to the top of the stairs and just sit there. Not sure if this is related to the bathroom/going to the door thing, as she’s also obsessed with going into the back room that we close off with a door. Any experience with breaking habits like these? We’ve been doing training and giving her food in the basement, but she knows her bag of food is upstairs. Or maybe this is truly a bathroom thing haha.