Things that need to show up as choices/moments
I think we should be able to make evil Rodrik and good Rodrik. I'm guessing Ramsay is at Ironrath pissed about Ironwood. He could demand that the Forresters deal with the problem else Ethan won't be the only Forrester he kills. This is where good/bad Rodrik comes in. Good option, use power granted by Boltons to assimilate Whitehills (they don't show up in books) by means of alliance or bad Rodrik sets up a Red Meeting of his own, replacing The Rains of Castamere with Talia's Song and playing the Lord Frey role of watching the slaughter play out. We could also end with a Lannisters send their regards note by walking up to Ludd and cramming bread and salt down his throat, "Here's your bloody bread and salt!!!"
Also, since the Hardhome battle was so epic make the White Walker encounter next episode (you know there'll be one) really special, crank things to 11.
Add your great choices and moments, hell, the devs might even take notice. Betcha they look at the forums for some ideas.
P.S. someone please photoshop Rodrik's face onto Lord Frey during Red Wedding and post it. If you feel up to the task, please make a gif with that and Ludd as Robb Stark.