Depending on the additives in the diesel I would expect "warm weather" diesel to be good to about -10 C and perhaps a bit lower so I wouldn't worry about that.

As you say the engine turns easily I'd be checking for fuel leaks and make sure the diesel system is primed.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!