I cannot recall a single flight ex VIE that left on time in the last 2 years, VIE is growing around 15 % yearly since a couple of years and the infrastructure is simply not there.Plus the usual thick fog in winter...
So based on a potential departure delay you are coming close to the MCT of 45 minutes, which is absurd anyway.
It is doable, but do yourself a favour and rebook yourself on an earlier flight, if it is not really inconvenient...