Whole set of 19 images was created in free time between commercial projects.
Its hard to estimate full work time, but it I started working on this about one year ago.

Every object in the scene is made with actual 3d geometry. There are few photoscanned assets created from scratch for this projects. I also used some assets I found online.
Most difficult asset to create was snowy tree visible in few images. Trunk model is photoscanned object I created a while ago as a side project. I decided to use it here with branches added in speedtree.
You can find tree asset for download on my behance project page.

Most important aspect for me was picking right lighting conditions for every image. I mostly used hdr mages sometimes mixed with corona sun.