A little behind on my re-watch but just powered through The Door and have BOTB on deck. After a second viewing, there's LOTS of suggestions and blatantly obvious actions by Sansa that suggest she'll call on LF to bring the Knights of the Vale to Jon's aid.
Now, does she do it in a deceitful way in order to make sure the majority of the casualties are wildlings? I don't know, maybe? But the first time I watched it, I was completely caught off guard when she showed up with LF, but on the re-watch, I realize I simply missed a lot of obvious signs.
Also... does young Hodor look like he is trying to hold something back while he's on the ground? My roommate suggested that he was mimicking the motions grown-up Hodor was doing to hold the door closed. The 3ER clearly takes Bran to that point in history with the intention of forcing him to corrupt Hodor's mind as a lesson to what happens when you interfere with the past. Right? The NK touched Bran, Bran freaks out, the 3ER says "it is time for you to become me" which I thought was the whole *downloading* thing, but as the WWs are entering the cave and killing the CotF, the 3ER has Bran back at old Winterfell for no reason at all other than to intentionally corrupt Hodor. The 3ER KNEW he would eventually have to teach Bran that lesson, but was trying to put it off for as long as he could and he could no longer put it off now that the WWs were about to kill him.