So the Sagas.
My 15 year olds Ogre Kingdoms Army sits on our big painting table where he, and my 8 and 6 year old paint figs, and I usually do assembly work and help them with questions and techniques.
As I was assembling my viking warband, I looked at his Ogres and thought about doing a Viking fantasy saga campaign.
Vikings, Ogres, trolls, goblinoids, dwarves, etc. snow covered battlefields, viking gods interfering, etc.
I don't know enough about the viking sagas, but thats what the internet is for.