Its also colder than this time last year, so that 110miles you got last year could equate to a further 10-12 miles lost this year (98 miles). Take into account having the heating on could essentially loose another 10% or so depending how you preheat the vehicle.
How many miles are you seeing once its fully charged using your home charger 125ish miles?
There are too many variables to come up with an exact figure such as speeds, road type etc, but loosing just over the half the vehicles range seems a bit much, when in reality you should be getting around the 100 +- 10 mark in sub zero temeratues.
What really surprises me with the Vivaro is the smaller battery is only 50Kw, whilst that may be sufficient for a small compact car like the e2008, it isn’t in what essentially is a work van.