The Easy Environments series for Daz Studio and Poser combines high-res 360° Skysphere/HDRI backgrounds with terrain geometry to place your characters on.

Winter II presents a lovely winter landscape.
The ground plane comes with several Morphs like foot and sled tracks.
Two of the foot tracks run side by side (for two figures walking together), the third track comes from the opposite direction (for figures meeting).
The scene loads with a Snow-Falling and a Snow-Drifting prop (hidden by default, unhide to use).

The HDRI (Iray) works well for "shadow-catching" renders without the geometry too.

The file formats are native .DUF for Daz Studio 3Delight and Iray, and .PP2 for Poser.

Lighting is included for all versions (Iray through the HDR environment, 3Delight parented to the skysphere, Poser as a separate preload).