VRayPhysicalCamera also provides the settings for vignetting, very handy even if it will be finely tuned during post production. While playing with exposure, we may continue with a more photographic approach, and change the white balance. When doing night photography, playing with WB can give nice, rich colors in seemingly plain light (Fig.10). I took these photos using Shaded / Cloudy settings, and tried to achieve some of that look in the scene, even if it was a starting to look bit too warm.

Fig.10
To illuminate the fog a bit, we need more light – we need the aforementioned ambient light. But we are not going to use the Ambient setting, nor will we use a Skylight solution. Sky will be handled by a big Vray Light above the whole scene, colored teal (Fig.11), and one smaller Vray Light, angled slightly towards the camera, placed just above the roof. Moonlight will be done using a standard Max Directional light, placed above the camera. Because I don't want the front facing walls to be lit too much, I built a simple shadow-caster object, simulating the other side of the street (Fig.12). For placing such lights, where shadow is even more important than the light, it's good to use viewport shadows display. I use it for almost all lights in the scene, but it really works well with one or two as with any more they tend to cancel each other out.
I didn't want any direct light on the front facing walls, but I wanted to suggest some world off screen. I used three Omni lights, projecting a quickly stitched image of tree branches, to simulate some streetlights hidden behind the trees (Fig.13).
At this stage with the main light sources in place, I took the low quality rendering into Photoshop, and started tweaking a bit. I quickly confirmed that most of the colors were way too saturated, producing an image that was way too warm. Quick try with Adjustment Layers provided the direction I should try (Fig.14). I also noticed that the side walls could use some specularity to accentuate the damp feeling and that there was no nice main specular on the street...