I think Sansa withdrew after Ramsay's brutality and it took her a while to get to the point where she could trust in people again. But I think in the end it showed her beginning to open up a bit more. I believe that she will be reserved; like how Ned was left even more reserved after the events of Robert's Rebellion.
I'll be honest, I don't see Sansa as manipulative at all. Manipulative people are rarely who they present themselves to be. They don't take responsibility for the things they've done, especially when there are disastrous consequences, and blame other people. Manipulative people generally disrespect boundaries, prey on someone's conscience/empathy, create plots and shit stir often just for the sake of drama, they generally target people more vulnerable than themselves, etc. That doesn't describe Sansa, in my opinion, that describes Cersei and Petyr. I think Sansa became more shrewd, which is different. People who are shrewd generally rely on being observant, being a good judge of character, out-thinking their opponents, etc. And I like that because Sansa's big weakness as a character in the earlier seasons was her flawed judgement in character; she survived by learning to consider people's motives, goals, likely responses given past behavior, etc. She didn't become a master assassin or great general or prophetic leader or Master of Coin with zero qualifications. She turned her weakness into one of her strengths.