Much. In the book, this variation does not exist, at all. They take a childhood friend of Sana (Jeyne Poole) and claim she is Arya Stark (the little sister) to marry Ramsay... who then is rescued, to a degree, by Theon Greyjoy. And Petyr is plotting a wedding of Sansa with an heir of Arryn (Harold Hardyng, yea... who?) so that she has a claim to the throne.
Who knows what the director of the TV series wants to show here, other than that Bolton is base and ruthless. He was far worse to Jeyne Poole in the book... and Theon did more than just watch.
Book 5 varied significantly from the HBO series, and it will be interesting to see if/how they pull things back together.
Maybe more interest would be to know how much the series has/is altering book 6, Winds of Winter. Martin is taking forever to finish it, it isn't done and they're filming HBO season 6... so I think we'll never know how much the HBO series caused the book to change to fit the divergence... Martin has said he wants to publish book 6 before the series airs, but it won't be before it is shot.
And there is to be a book 7... A Dream of Spring, which has no chance of being written before the series. I'm guessing he is just outlining the big picture... but this is going to be a mess. HBO/directors will probably have more to say about how the series finishes than Martin, to a degree. Too much money, a huge hit and the budget and schedule all tied up... the screenwriters are going to be getting an outline, and finishing the scenes. If you're a fan of the books, I think it likely HBO is controlling more than you would want, as they work to a schedule, while Martin has taken his time to finish.