We have a dusting of about 2 cm, roads are clear though.
Re: your starting problem reminds me of when we first bought the Mav, it failed to start so under warrenty they checked the battery said all was fine. I charged it and next day it failed to start again, had to jump start it off the wife's Fiesta.
I told them about the embarrassment of having a 4x4 in the snow, and having to jump start it off a 1.3 Fiesta.:nenau
They saw the funny side and placed a new one on it straight away.
Problem solved. :thumb2
These batteries take a real pasting when the weather is cold.
Your battery will loose more than 10% capability, so if the Disco was only just starting then this cold weather will kill it.
If in doubt, replace the battery.