Download Viking Village Free Unity
This pack contains 7 houses and 14 design models to make a Viking town. There is an example scene and there are LODGroup prefabs for each model to render with as fewer polygons as could reasonably be expected. Structures have up to 4 LOD stages included, in addition to some of them have insides.
Here are scarcely any instances of LOD polycount:
Longhouse LOD0-4271, LOD1-2350, LOD2-1872, LOD3-348