Does it give a sort of dead thunk on turning the key but you hear the starter spin with a whir (and the starter doesn't engage the ring gear)?

Sounds like a sticking starter solenoid due to the near to below temps.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.