My DH had a shoulder reconstruction/rotor cuff repair done because his shoulder kept dislocating. It was his right shoulder and he is right-handed. He wasn't allowed to move his shoulder at all for about 6 weeks. It was about 4 years ago so I'll see what I can remember.
He was in hospital for one night only. I helped him into his pjs before I left for the night. It was quite funny because they had given him ketamine for the pain relief and he was a bit loopy and couldn't even figure out how to put his foot into his pj pants! His pj top was a t-shirt I think and it just went over the whole sling and arm so the arm was under the shirt. It was a large shirt. The hospital advised that button up shirts would be the easiest thing to wear, and that is what he wore during the day for a few weeks. We managed to work out how to get a t-shirt on though. Put the operated arm through the sleeve first, guide the shirt up the arm until it is in position and then over the head and other arm. I would imagine you could do the same for a bra as long as someone can help you do it up.
My DH was in a lot of pain afterwards and I had to bath, dry and dress him for about a week. After that I had to help him dry and dress. He was able to shave by himself, and brush and floss his teeth. He practised this before the operation. To floss his teeth we bought a thing from a pharmacy that looks a bit like a slingshot stick that you wind your own floss onto (the slingshot elastic) and it was great. He also practised wiping his bum with his left hand. Something to think about! Doing his hair wasn't an issue because he has short hair that is pretty much wash and wear.
The biggest annoyance from his shoulder operation is that he couldn't drive until his sling was off about 6 weeks later. I don't have a licence so it was buses and granny trolleys to get our groceries.
His shoulder is great now and he can throw our toddler around with no problems at all. Previously anything "overarm" would have dislocated it. I hated having to relocate if for him.
Let me know if you have any other questions and I'll try to help.