I am stuck at an earlier point in the Winter is Coming questline and it appears you are SOL if Robb Stark dies as you can't continue the quest with Roose Bolton. And someone else said that you can keep Robb Stark alive if you intervent in the Red Wedding and his NPC lives, but when I have tried to intervene it seems impossible to save him as he usually gets knocked out very fast at the start and I have to try to get around/ or through a bunch of my own troops just to get to him.

when i tried to stop the red wedding, it inadvertantly forced me to side with the riverlanders.. not to mention that its just too difficult to do anything in this mod at all.

You can stop the Red Wedding right and keep Robb Stark alive. You will need to tweak the damage settings against Heroes and Lords so that it does the minimum damage and to boost the Heroes and Lords damage to 3x. When you spawn inside the keep, do not rush upstairs but rather charge into the center of the lower floor and take the aggression off Robb who is surrounded by 4-5 enemies. After that, you should shield Robb from the crossbowmen upstairs until the rest of your troops have taken them out.

I kept pressing the 'U' key for the leadership healing to allies during the battle. If all goes well, King Robb Stark and Jon Umber will head back up to Winterfell and The Twins and The Dreadfort will change hands to the Westerlands.

leadership healing? what is that? i guess he mustve bled out on the way upstairs then.....its been 600 days...sheesh.