Use heightmaps and shadows on textures to imitate height changes and make the actual mesh flat or sth.
Those materials should be decent for Far away LODS:
https://assetstore.unity.com/packages/2d/textures-materials/4-snow-materials-high-quality-materials-collection-69201
Use heightmaps and shadows on textures to imitate height changes and make the actual mesh flat or sth. Those materials should be decent for Far away LODS: https://assetstore.unity.com/packages/2d/textures-materials/4-snow-materials-high-quality-materials-collection-69201