Moving to a New Apartment

My partner and I adopted a 1 year old daschund/chi mix from a shelter back during Christmas and are looking for advice on how to minimize barking for when we move to our new apartment. Our girl is moderately reactive to people and very reactive to other dogs (barking at people and barking and lunging at dogs). This started about 3 weeks after we adopted her. We never really have people over so this isn’t a problem and her reactivity is manageable on walks and trips to go potty. After 2.5 months, she has really begun to chill out and is finally able to settle and go to sleep on her own during the day without enforced naps. I would say she is a pretty normal-ish barker, but she barks when she gets frustrated and I don’t know how to fix it. There are three times she barks 1) trying to get food from the counter, 2) reacting to things she sees or hears (mostly has been solved with some privacy film on the windows) and 3) frustration about being crated or left alone at home. She responds well to corrections for the first and second situation. It is usually a few barks and then she stops so within a completely normal amount, but I am worried about the barking when left. It isn’t seperation anxiety because if I leave or crate her while she is already sleeping or resting she doesn’t bark at all, but if I crate her or leave her while she’s active or awake she gets frustrated and will bark or whine for a few minutes probably 3-7 before settling and going to sleep. I have always ignored her barking, but it hasn’t worked even though I have been very consistent. I think the barking itself is rewarding because she is just frustrated and so barking relieves her frustration a little. I am hesitant to use the frozen kong trick because she is only 12 lbs and it wouldn’t take much extra food for her to become overweight. Right now, we live in a pretty soundproof townhouse so it isn’t a big deal, but we are moving in June and I am so paranoid that we will get a complaint and have to rehome her. Is there really any solution to this other than a long lasting treat? I tried busy bones, but they don’t last long enough for her to not start barking once she finishes.