(Spoilers Extended) A theory about how the Others came back

I was thinking about what Alys told Aemond in the show about being the wife/mistress of King Harren, and "talking to things in the forest" to try to save her boy.

If she's an old woods witch and an "agent" of sorts of the Old Gods/weirwoods/COTF, is it possible that she orchestrated or encouraged of the Battle over the God's Eye?

The Children are almost extinct and don't have the numbers to do a big blood sacrifice (like they supposedly did for the Hammer of the Waters when they sacrificed their own children), but two Targaryen princes, powerful dragonriders no less, and two massive dragons would make for a really huge blood sacrifice.

It could give them enough magical power/strength to start summoning or creating the Others again (or whatever it is they did in the first Long Night).