Why I Feel SanSan is Canon
I’ve always felt that Sansa didn’t recognize her attraction to Sandor while in KL in part due to her age, her circumstances as a prisoner, and the extreme mistreatment she suffered in KL. Subconsciously though she gravitated towards Sandor. She felt safe with him because even though his actions and words were frequently frightening, he had shown her a side of himself on multiple occasions which was caring, even tender, towards her.
Sandor also gravitated towards Sansa. I feel Sandor was attracted to her in KL and he didn’t know how to deal with it. Or, he too might not even have realized he was experiencing an attraction. He has major anger and self-esteem issues, he likely suffers from a form of PTSD, and is struggling with alcoholism. Not the ideal scenario to deal to begin with and then throw in an attraction to his King’s betrothed and he’s on overload emotionally. Deflect and deny.
What screams SanSan to me is the way they both think of and/or speak about the other post-BotB. Sansa has matured and her thoughts on Sandor come in the form of wishing he were with her, wondering what happened to him, having his image come to mind instead of Tyrion’s when she is dreaming about her wedding night, thinks about how Lothor Brune reminds her of Sandor, and finally, she kept Sandor’s cloak. Keeping the cloak is huge to me. For one thing, its risky if someone were to find it so there had better be a really good reason to keep it. Such as a romantic attraction.
On the other side, Sandor talks about Sansa to Arya, tells her of how he rescued her from the mob, he talked about pledging to Robb after returning Arya (before the red wedding), and finally the fact that he took care of Arya despite finding out there would be no gold forthcoming to him to ransom her. Should he ever meet up with Sansa again, he would look a hero in her eyes for helping her sister.
If SanSan isn’t canon, I don’t know what is. Please GRRM, make this happen!